Using only four 4's and any operational sign find the value of 8

Answers

Answer 1

Answer:

The answer is 4 + 4 + 4 - 4 = 8

Step-by-step explanation:

The four fours problem is one of the problems given in the book "The Man Who Calculated" by Malba Tahan, a Brazilian-born professor of mathematical sciences.

There are many complicated problems in this book made with the intention of using logic to find a value.

The 4 fours problem is based on using these numbers and using any operation to result in the numbers 1 through 10.


Related Questions

what number should replace the question mark

Answers

Answer: The missing number is 5.

Step-by-step explanation:

In the table we can only have numbers between 1 and 9,

The pattern that i see is:

We have sets of 3 numbers.

"the bottom number is equal to the difference between the two first numers, if the difference is negative, change the sign, if the difference is zero, there goes a 9 (the next number to zero)"

Goin from right to left we have:

9 - 6 = 3

6 - 2 = 4

4 - 9 = - 5 (is negative, so we actually use -(-5) = 5)

4 - 4 = 0 (we can not use zero, so we use the next number, 9)

3 - 3 = 0 (same as above)

? - 1 = 4

? = 4 + 1 =  5

The missing number is 5.

4) What is the perimeter of a square with side length Of 3 squared

Answers

Answer:

36

Step-by-step explanation:

3² = 9.

So, the perimeter is 9(4) = 36

Find x in each triangle

Answers

Answer:

x=20

Step-by-step explanation:

Since this is a right triangle, we can use the Pythagorean theorem

a^2 + b^2 = c^2

21 ^2 + x^2 = 29^2

441+x^2 =841

Subtract 441 from each side

x^2 = 841-441

x^2 = 400

Take the square root of each side

sqrt(x^2) = sqrt(400)

x = 20

Answer:

[tex]\boxed{x = 20}[/tex]

Step-by-step explanation:

Hey there!

Well to find x we need to use the Pythagorean Theorem, which is.

[tex]a^2 + b^2 = c^2[/tex]

We have a which is 21 and 29 which is c.

[tex](21)^2 + x^2 = (29)^2[/tex]

[tex]441 + x^2 = 841[/tex]

[tex]-441[/tex]

[tex]x^2 = 400[/tex]

[tex]x = 20[/tex]

So the missing side "x" is 20.

Hope this helps :)

A Prefeitura da Cidade Feliz doou um
terreno para a Comunidade Viver Bem
discutir projetos que deveriam ser
implantados no local. Após um planejamento
participativo, ficou acertado que 45% da área
total desse terreno serão destinados a uma
creche;
3%,
para banheiros públicos e 12%
para uma academia de ginástica comunitária.
A sobra da área, que é de 960m² será
utilizada para uma pequena praça com
parque de lazer. Qual é a área total ocupada
pela creche, banheiros públicos e academia
de ginástica comunitária?

Answers

Aqui temos a seguinte divisao de terreno:

creche + banheiros + academia = 45% + 3% + 12% = 60%

O que sobra: Fazendo a conta, 100 - 60 = 40, restará 40%

No enunciado informa que sobraram 960m².

Logo concluimos que 40% = 960m²

Sendo assim, regra de 3:

   m²                %

  960   --------   40

    X     --------   60

40X = 960 . 60

X = 57600/40

X = 1440

Logo 1440m² é destinado para: creche, banheiros públicos e academia

de ginástica comunitária.

O terreno tem um total de 1440 + 960 = 2400m²

para cada espaço - novamente diversas regra de 3:

→ creche = 45%

    m²                  %

  2400   --------   100

    X        --------    45

X = 108000/100 = 1080

 

→ banheiros públicos  = 3%

    m²                  %

  2400   --------   100

    X        --------    3

X = 7200/100 = 72

→ academia de ginástica comunitária = 12%

    m²                  %

  2400   --------   100

    X        --------    12

X = 28800/100 = 288

provando:

60% = 1440m²  (visto acima)

creche - 1080

banheiros - 72

academia - 288

1080 + 72 + 288 = 1440 (60%)

Which statements about the sum of the interior angle measures of a triangle in Euclidean and non-Euclidean geometries are true? A. In Euclidian geometry the sum of the interior angle measures of a triangle is 180 degrees, but in elliptical or spherical geometry the sum is less than 180 degrees. B. In Euclidian geometry the sum of the interior angle measures of a triangle is 180 degrees, but in elliptical or spherical geometry the sum is greater than 180 degrees. C. In Euclidian geometry the sum of the interior angle measures of a triangle is less than 180 degrees, but in hyperbolic geometry the sum is equal to 180 degrees. D. In Euclidian geometry the sum of the interior angle measures of a triangle is greater than 180 degrees, but in hyperbolic geometry the sum is less than 180 degrees. E. In Euclidian geometry the sum of the interior angle measures of a triangle is 180 degrees, but in hyperbolic geometry the sum is less than 180 degrees.

Answers

Answer:

its b and e

Step-by-step explanation:

The statements given in options B and E are   true so options B and E are right options.  

Given some statements we have to determine that which of the following statements are true

The given statements are as follows

A. In Euclidean geometry the sum of the interior angle measures of a triangle is 180 degrees, but in elliptical or spherical geometry the sum is less than 180 degrees.

B. In Euclidean geometry the sum of the interior angle measures of a triangle is 180 degrees, but in elliptical or spherical geometry the sum is greater than 180 degrees.

C. In Euclidean geometry the sum of the interior angle measures of a triangle is less than 180 degrees, but in hyperbolic geometry the sum is equal to 180 degrees.

D. In Euclidean geometry the sum of the interior angle measures of a triangle is greater than 180 degrees, but in hyperbolic geometry the sum is less than 180 degrees.

E. In Euclidean geometry the sum of the interior angle measures of a triangle is 180 degrees, but in hyperbolic geometry the sum is less than 180 degrees.

We know some facts about each type of geometry

In Euclidean geometry  plane is used to plot the points and line.

In spherical geometry uses the sphere to plot the points and circles

Elliptical geometry is such a geometry where no parallel lines exists.

The sum of interior angles of a triangle is dependent on the type of geometry we are dealing with   and they can be written down in the following points

In Euclidean geometry the sum of interior angles of  a triangle is 180° In spherical or elliptical geometry the sum of interior angles of a triangle is more than 180°  In hyperbolic geometry  the sum of interior angles  of a triangle is less than 180°  

So from the above observations we can conclude that statements given in options B and E are   true so options B and E are right options.  

For more information please refer to the link given below

https://brainly.com/question/4637858

In the Brady's Family, each girl has twice as many brothers as she has sisters.
However, each boy has the same number of brothers as sisters. Is this possible; and
if so how many girls are there in the family, and how many boys?

Answers

Answer:

3 girls and 4 boys

Step-by-step explanation:

Writing the number of girls in the family as g and the number of boys in the family as b,

we know that each girl has twice as many brothers as sisters. Therefore, the amount of boys in the family (b, or how many brothers each girl has) is twice the number of the amount of girls in the family (g) minus 1 (g-1) (subtract 1 because each girl's number of sisters does not include the girl herself). We can write this as

b = 2(g-1)

Next,

we know that each boy has the same amount of brothers as sisters. Therefore, the amount of boys in the family minus 1 (b-1, subtracting 1 because we don't include the boy that has the brothers) is equal to the amount of girls in the family (g). we can write this as

b-1 = g

Therefore, we have

b = 2(g-1)

b-1 = g

Plugging b-1 = g into the first equation, we get

b = 2 (g-1)

2(g-1) = 2((b-1) - 1) = b

= 2(b-1-1)

= 2(b-2)

= 2b-4

b = 2b-4

subtract 2b from both sides to make it so that only b values and their coefficients are on one side

-b = -4

multiply both sides by -1 to solve for b

b=4

Therefore, there are 4 boys in the family and b-1 = 4-1 = 3 girls in the family.

Find the solution of the inequality 5 > r - 3.
A) r<2
B) r = 2
C) r=8
(D) r < 8​

Answers

Answer:

[tex]\huge\boxed{r<8}[/tex]

Step-by-step explanation:

[tex]5 > r - 3[/tex]

Adding 3 to both sides

[tex]5 + 3 > r[/tex]

[tex]8 > r\\OR \\r < 8[/tex]

Answer: D. r<8

Step-by-step explanation:

[tex]5>r-3[/tex]

add 3 to both sides

[tex]r-3+3<5+3[/tex]

[tex]5+3=8[/tex]

simplify

[tex]r<8[/tex]

Consider the following ordered data. 6 9 9 10 11 11 12 13 14 (a) Find the low, Q1, median, Q3, and high. low Q1 median Q3 high (b) Find the interquartile range.

Answers

Answer:

Low             Q1                Median              Q3                 High

6                  9                     11                      12.5                14

The interquartile range = 3.5

Step-by-step explanation:

Given that:

Consider the following ordered data. 6 9 9 10 11 11 12 13 14

From the above dataset, the highest value = 14  and the lowest value = 6

The median is the middle number = 11

For Q1, i.e the median  of the lower half

we have the ordered data = 6, 9, 9, 10

here , we have to values as the middle number , n order to determine the median, the mean will be the mean average of the two middle numbers.

i.e

median = [tex]\dfrac{9+9}{2}[/tex]

median = [tex]\dfrac{18}{2}[/tex]

median = 9

Q3, i.e median of the upper half

we have the ordered data = 11 12 13 14

The same use case is applicable here.

Median = [tex]\dfrac{12+13}{2}[/tex]

Median = [tex]\dfrac{25}{2}[/tex]

Median = 12.5

Low             Q1                Median              Q3                 High

6                  9                     11                      12.5                14

The interquartile range = Q3 - Q1

The interquartile range =  12.5 - 9

The interquartile range = 3.5

7(a-1)=45 what is the answer to that equation????

Answers

Answer: a = 52/7

Step-by-step explanation:

remove the parentheses, move the constant to the right, calculate, then divide both sides

Answer:

The answer is, a = 52/7, or a = 7.42 in decimal form

Follow the steps below for better explanation:

Nhà trường muốn đánh giá tỉ lệ chăm học của sinh viên (trong một tuần). Khảo sát 236 sinh viên thì thấy có 32 sinh viên chăm học. Hãy ước lượng khoảng đối xứng cho tỉ lệ sinh viên chăm học của trường với độ tin cậy 95%

Answers

Answer:

can't understand the language

please find the answer

Answers

Answer:

I hope this is correct but 8.5 or 8 1/2 Units

Answer:

i think it is 8 1/2.

Step-by-step explanation:

my reasoning is that because v=lwh. the length is 4 and hw is 2 1/8. so i multiplied those together.

A rectangular window is 48 in long and 36 in wide. Lisa
would like to buy a screen for the window. The cost of
the screen is based on the number of square feet the
screen is. Use the facts to find the area of the window in
square feet.
Conversion facts for length
1 foot (ft) 12 inches (in)
1 yard (yd) = 3 feet (ft)
1 yard (yd) = 36 inches (in)
2
Х
$
?

Answers

Length=48inBreadth=36in

[tex]\\ \sf\longmapsto Area=Length\times Breadth[/tex]

[tex]\\ \sf\longmapsto Area=48(36)[/tex]

[tex]\\ \sf\longmapsto Area=1728in^2[/tex]

[tex]\\ \sf\longmapsto Area=144ft^2[/tex]

[tex]\\ \sf\longmapsto Area=48yard^2[/tex]

What is distributive property???

Answers

A number multiplied by a sum is the same as the sum of the number multiplied by each addend; a(b + c) = ab + ac

Answer:

the distributive property of binary operations generalizes the distributive law from elementary algebra, which asserts that one has always For example, one has One says that multiplication distributes over addition.

does x-2/x-6 simplify to 1/3 ?
explain why or why not ​

Answers

Answer:

no it is not 1/3

Step-by-step explanation:

(x-2) / (x-6)

This does not simplify

Rewriting x-2 as (x-6 +4)

(x-6 +4)/ ( x-6)

Replacing x-6 as m

( m+4) /m

Simplifying

m/m + 4/m

1 + 4/m

Replacing m with x-6

1 + 4/ ( x-6)

This is not 1/3

3.06 as. a fraction PLEASE HELP​

Answers

Answer:

153/50

Step-by-step explanation:

3.06

Rewriting as

There are two numbers after the decimal so we put the number over 100

306/100

Divide top and bottom by 2

153/50

To write 3.06 as a fraction you have to write 3.06 as numerator and put 1 as the denominator. Now you multiply numerator and denominator by 10 as long as you get in numerator the whole number.

3.06 = 3.06/1 = 30.6/10 = 306/100

And finally we have:

3.06 as a fraction equals 306/100

WORTH 100 POINTS!
The function h(x) is quadratic and h(3) = h(-10) = 0. Which could represent h(x)?

1) h(x) = x2 - 13x - 30
2) h(x) = x2 - 7x - 30
3) h(x) = 2x2 + 26x - 60
4) h(x) = 2x2 + 14x - 60

Answers

Answer:

h(x) = 2x^2 +14x -60

Step-by-step explanation:

A quadratic is of the form

h(x) = ax^2 + bx +c

h(3) = h(-10) = 0

This tells us that the zeros are at x=3 and x = -10

We can write the equation in the form

h(x) = a( x-z1)(x-z2) where z1 and z2 are the zeros

h(x) = a(x-3) (x- -10)

h(x) = a(x-3) (x+10)

FOIL

h(x) = a( x^2 -3x+10x-30)

h(x) = a(x^2 +7x -30)

Let a = 2

h(x) = 2x^2 +14x -60

It means

zeros are 3 and -10

Form equation

y=x²-(3-10)x+(-10)(3)y=x²+7x-30

Multi ply by 2

y=2x²+14x-60

Option D

Dan weighs 205 pounds but is only 5 feet 8 inches tall. Evan is 6 feet tall. How much would you expect Evan to weigh if they have the same height/weight ratio? WILL MARK BRAINLIST

Answers

Answer:

Around 217 pounds

Step-by-step explanation:

Let's convert the height into inches.

5 feet 8 = [tex]5\cdot12 + 8 = 60 + 8 = 68[/tex]

6 feet [tex]= 6\cdot12 = 72[/tex].

We can set up a proportion

[tex]\frac{205}{68} = \frac{x}{72}[/tex]

We can use the cross products property to find x.

[tex]205\cdot72=14760\\\\\\14760\div68\approx217[/tex]

Hope this helped!

Answer:

217.0588235 lbs

Step-by-step explanation:

Convert ft inches to inches

5 ft = 5*12 = 60 inches

5 ft 8 inches = 68 inches

6 ft = 6*12 = 72 inches

We can use ratios to solve

205 lbs        x lbs

------------- = ----------------

68 inches     72 inches

Using cross products

205 * 72 = 68x

Divide by 68

205 *72/68 = x

217.0588235 lbs

on a particular day, a man spent 12 minutes more driving to his office than driving home. His average speed from home to office is 12km/h and from office to home is 60m/h .How far is the man home to his office ​

Answers

Answer:

distance between home and office = 3 km

Step-by-step explanation:

Question: Complete the point-slope equation of the line through (1,3)and (5,1). Use exact numbers. Equation: y-3=(Answer ?)

Answers

Answer:

y - 3 = -1/2(x - 1)

Step-by-step explanation:

Hey there!

Well point slope form is,

[tex]y - y_{1} = m(x - x_{1})[/tex]

We can use the point (1,3)

y - 3 = m(x - 1)

Now we need to find slope with the following formula,

[tex]\frac{y^2-y^1}{x^2-x^1}[/tex], we’ll use the points (1,3) and (5,1).

[tex]\frac{1-3}{5-1}[/tex]

-2/4

Slope or m = -1/2

y - 3 = -1/2(x - 1)

Hope this helps :)

plz hep me to prove the following relations:​

Answers

Step-by-step explanation:

[taking alpha = a]

L.H.S.

(1-sin⁴a)/cos⁴a

= 1/cos⁴a-sin⁴a/cos⁴a

= sec⁴a-tan⁴a

= (sec²a+tan²a)(sec²a-tan²a)

= (1+tan²a+tan²)(1) [as sec²a=1+tan²a]

= 1+2tan²a

= R.H.S. [Proved]

These two triangles are congruent by the Hypotenuse-Leg Theorem.

Answers

Answer:

[tex] y = - 2 [/tex]

Step-by-step explanation:

Given that the 2 triangles are congruent based on the Hypotenuse-leg theorem, this implies that:

[tex] x - y = x + 2 [/tex] , and [tex] 2x - y = 4x + 2y [/tex]

Using the expression, [tex] x - y = x + 2 [/tex], solve for y:

[tex] x - y - x = x + 2 - x [/tex]

[tex] - y = 2 [/tex]

[tex] y = - 2 [/tex]

What is the prime factorization of 75

Answers

Step-by-step explanation:

The prime fractorization of 75 is 3×5×5 or 3×52

I need help pls. Algebra

Answers

Answer:

The answer is option A

Step-by-step explanation:

f(x) = (x+1)³ + 4

To find f-¹(x) equate f(x) to y

That's

y = (x+1)³ + 4

Next interchange the terms x becomes y and y becomes x

That's

x = ( y+1)³ + 4

Make y the subject

(y+1)³ = x - 4

Find the cube root of both sides

That's

[tex]y + 1 = \sqrt[3]{x - 4} [/tex]

Send 1 to the right side of the equation

That's

[tex]y = \sqrt[3]{x - 4} - 1[/tex]

So we have the final answer as

[tex]f ^{ - 1} (x) = \sqrt[3]{x - 4} - 1[/tex]

Hope this helps you

Answer:

option 1

Step-by-step explanation:

f(x)=(x+1)³+4

to find the inverse interchange the variable and solve for y

inverse f(x)=(y+1)³+4

x=(y+1)³+4

x-4=(y+1)³

y+1=∛x-4

y=∛x-4 -1

Ashton needs to rent a car while on vacation. The rental company charges $19.95, plus 18 cents for each mile driven. If Ashton only has $50 to spend on the car rental, what is the maximum number of miles she can drive?

Answers

Answer:

166.9 miles or 166 miles

Step-by-step explanation:

We can form an equation like this:

19.95 + .18x = 50

In this equation, "x" is the number of miles.

=> 19.95 - 19.95 +.18x = 50 -19.95

=> .18x = 30.05

=> .18x/.18 = 30.05/.18

=> x = 166.9

Ashton can drive 166.9 miles.

**Note: We cannot round the answer to 167, as she would not have enough money to drive the extra 0.1 mile.

Given the sequence 38, 32, 26, 20, 14, ..., find the explicit formula. A. an=44−6n B. an=41−6n C. an=35−6n D. an=43−6n

Answers

Answer:

The answer is option A

Step-by-step explanation:

The sequence above is an arithmetic sequence

For an nth term in an arithmetic sequence

A(n) = a + ( n - 1)d

where a is the first term

n is the number of terms

d is the common difference

From the question

a = 38

d = 32 - 38 = - 6 or 20 - 26 = - 6

Substitute the values into the above formula

A(n) = 38 + (n - 1)-6

= 38 - 6n + 6

We have the final answer as

A(n) = 44 - 6n

Hope this helps you

Answer:

a

Step-by-step explanation:

you're welcome!

how many 50 cents coins are there in $10:50​

Answers

Answer:

21

Step-by-step explanation:

you divide 10.50 by 50

10 times as much as 9

Answers

Answer:

90

Step-by-step explanation:

10 x 9

=> 90

10 times 9 is 90.

The margin of error ________ (increases or decreases) with an increased sample size and ________ (increases or decreases) with an increase in confidence level.

Answers

The margin of error decreases with an increased sample size and increases with an increase in confidence level.

With such a larger sample size, the margin of error lowers (grows or decreases), whereas, at a higher confidence level, it increases (increases or declines).

The margin of error:

A margin of error increases as the confidence level rises, resulting in a larger interval. A margin of error is reduced as confidence is increased, resulting in a narrower interval.By increasing sample size and confidence level, the margin of error lowers and grows.

             Margin of error [tex](E) = Z_c * {\frac{\sigma}{\sqrt{n}}}[/tex]

Here [tex]Z_c[/tex] denotes the confidence level's critical value.Whenever it comes to sample size, n is the number of people who take part in the study.As a result, the margin of error lowers as the sample size grows, and the margin of error increases as the confidence level grows.

Find out more about the margin of error here:

brainly.com/question/10501147

Stephen Curry's record during the 2017 - 2018 NBA final game is made up of 2-point shots and 3-points.

His total points scored for the final game was 45 points with 19 shots made. How many 2-point shots did

he make? How many 3-point shots did he make?

2-Pointers:

3-Pointers:

Answers

Answer:

x =  12      ( two points shots )

y =  7       ( three points shots )

Step-by-step explanation:

Let´s call  "x" two points shots,  and  "y" three points shots, then

x  +  y  =  19

2*x  +  3*y  =  45

We have to solve a two-equation system for x and y

y =  19  - x

2*x  +  3 * ( 19 - x ) = 45

2*x  +  57  -  3*x   =  45

- x   =  45 - 57

-x   =  - 12

x  = 12

And     y  =  19  -  12

y  = 7

(-2×3)+(3×2) how do we solve it​

Answers

Answer:

0

Step-by-step explanation:

- 2×3= - 6

2×3=6

-6+6=0

Answer:

0

Step-by-step explanation:

first

(-2x3)+(3x2)

-6+6=0

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