Solve the equations below. Give exact solutions only. Show your work.

a) 5x^2 - 7 = 72
b) x(x + 2) = 5
c) 3x^2 + 2x - 4 = 0

Answers

Answer 1

Answer:

A. 5x² - 7 - 72 = 0

5x² - 79 = 0

x = ± √-4ac / 2a

x = ± √- 4 (5) (-79) / 2 (5)

x = ± √ 1580 / 10

x = ± 39.749/10

x = + 39.749/10 x = -39.749/10

= 3.9749 = - 3.9749

B. x² + 2x - 5 = 0

x = - b ± √b² - 4ac / 2a

= - 2 ± √2² - 4 (1) (-5) / 2 (1)

= - 2 ± √4 + 20 / 2

= - 2 ± √ 24 / 2

x = - 2 + 4.898 /2 x = - 2 - 4.898 / 2

= 2.898/2 = -6.898/2

= 1.449 = - 3.449

C. 3x² + 2x - 4 = 0

x = - b ± √b² - 4ac / 2a

= - 2 ± √2² - 4 (3) (-4) / 2 (3)

= - 2 ± √4 + 48 / 6

= - 2 ± √ 52 / 6

x = - 2 + 7.211 /6 x = - 2 - 7.211 / 6

= 5.211/6 = - 9.211 /6

= 0.869 = - 1.535

Hope that helps

Please to re-check answers


Related Questions

There are 900 seats on a train. 540 of the seats are empty. What percentage of the seats on the train are empty?

Answers

60% of the seats on the train are empty

you have to divide 900 by 9 to get 100 because percents are out of 100, then you have to divide 540 by 9 also.

Answer:

60%

Step-by-step explanation:

Because there are 540 empty, and 900 total, you need to divide 540 by 900.

540/900=54/90=6/10=60/100

When you get 60/100, or 0.6, you know that it is 60 percent because percent is out of 100.

Mr.Wedmore works at a car dealership and earns a monthly salary of $2,000. He also earns 25% commission on the gross profit of the car sales. If Mr.Wedmore brought in $10,000 worth of profit, for the dealership, how much would he earn this month

Answers

Answer:

25% of 2000= 500

25% of 10000= 2500

Step-by-step explanation:

If and , find .

A.

B.

C.

D.

Answers

Answer: GOONNA BE BE SIRRRRR BTW I HAVE IPHONE 21345678

Step-by-step explanation:

one of the angles of a regular octagon has a measure of (7x-5) What is the value of x?

Answers

Answer:

  x = 20

Step-by-step explanation:

The interior angles of a regular octagon have measures of ...

  180° -360°/8 = 135°

We want that equal to the given expression.

  7x -5 = 135

  7x = 140 . . . . add 5

  x = 20 . . . . . divide by 7

The value of x is 20.

Answer:

20

Step-by-step explanation:

Regular octagon means that each angle is 135 degrees, so 135 = (7x - 5).

135 = 7x - 5,

135 + 5 = 7x,

140 = 7x,

140 / 7 = x,

20 = x

Rachel bought a sheet of fifty 34-cent stamps from the post office. she paid for the stamps with a $20 bill. how much money should she get back?

Answers

50 x 0.34 = 1.70
20 - 1.70 = 18.30

Mrs. Hill went to get an oil change, because she has a 20% off coupon. If the oil change is 35.00, how much is the discount?
In problem #1, how much does Mrs. Hill have to pay?

Answers

The discount is $7, and Mrs.Hill only has to pay $28.

Answer:

28.00

Step-by-step explanation:

A mirror is 24 inches high and 28 inches wide. The center of the mirror will hang 514 feet from the floor on a wall that is 8 feet high. What will be the distance from the top of the mirror to the ceiling once the mirror is hung on the wall?.

Answers

The distance from the top of the mirror to the ceiling once the mirror is hung on the wall is 21 inches

The dimension of the mirror is given as:

[tex]Height = 24\ in[/tex]

[tex]Width = 28\ in[/tex]

From the center of the mirror to the floor of the wall, the distance is:

[tex]Distance =5\frac14\ ft[/tex]

So, the distance to the top of the mirror will be:

[tex]Top = 5\frac 14\ ft + \frac 12 \times Height[/tex]

Substitute 24 for height

[tex]Top = 5\frac 14\ ft+ \frac 12 \times 24\ in[/tex]

[tex]Top = 5\frac 14\ ft+ 12 \ in[/tex]

Convert feet to inches

[tex]Top = 5\frac 14\times 12\ in+ 12 \ in[/tex]

[tex]Top = 63\ in+ 12 \ in[/tex]

[tex]Top = 75 \ in[/tex]

The distance from the top of the mirror to the ceiling is the difference between the height of the wall and 75 inches.

So, we have:

[tex]Distance = 8\ ft - 75\ in[/tex]

Convert feet to inches

[tex]Distance = 8\times 12\ in - 75\ in[/tex]

[tex]Distance = 96\ in - 75\ in[/tex]

[tex]Distance = 21\ in[/tex]

Hence, the distance is 21 inches

Read more about lengths at:

https://brainly.com/question/10545161

Nolan began a savings account three years ago. He invested $100 at a 2% interest rate according to the equation Vn = 100(1.02)x, where Vn is the value of his account after x years. Anias started an account today. She invested $100 at a 2% interest rate according to the equation Va = 100(1.02)x–3, where Va is the value of her account. Let’s say Anias started saving at the same time Nolan did, three years ago. Approximately how much money would she have had to invest to have the same amount of money she has now?
$5.77
$90.24
$94.23
$106.12

Answers

Answer: 94.23

Step-by-step explanation:

solve one step equation x - 10.5 = 2.5

Answers

Answer:

x = 13

Step-by-step explanation:

need to solve for x so we get it by itself by adding 10.5 on the left side to cancel it out. what you do to one side you do to the other so since we added 10.5 to the left we need to add 10.5 to the right 10.5 + 2.5 =13

pls help pls no links ​

Answers

Answer:

d

Step-by-step explanation:

when you are dividing like numbers with different exponents, subtract them

In AWXY, WY is extended through point Y to point Z, mZYWX = (20 + 12)",
,
mZWXY
(2x + 5)", and m_XYZ = (7x - 1). What is the value of x?

Answers

2x+7=yxz hope this help i was confused

Use a model to solve ten multiplied by three sevenths . Leave your answer as an improper fraction.

Group of answer choices

thirteen sevenths

thirty seventieths

thirty sevenths

thirteen seventeenths

Answers

Answer:

30/7

Step-by-step explanation:

use desmos ( look it up(

Three men can build a wall in 8 days. How long will it take them if they have the help of 2 boys? Assume that each boy works half as fast as each man.​

Answers

Uhmm I think around 70 days or 90

I'm not sure

Answer:

6 days

Step-by-step explanation:

1 boy workload = 1/2 1 man workload

2 boys workload = 1/2*2 = 1 man workload

so 3 men + 2 boys workload = 4 men workload

3 men .....   8 days ... 24man-days to build

4 men .....   x days ... 24man-days to build

x=24/4=6

can you please help me with this question please

Answers

Answer:

c=$214.28

Step-by-step explanation:

Since you have the (p) value (p=285.7) all you need to do is plug it into one of these two equations

c=0.75p --- c=0.75(285.7)= 214.275-- 214.28

c=0.4p+100 --- c= 0.4(285.7) + 100 --- c= 114.28 +100 -- c= 214.28

either way its the same, just plug it into one or the other

Find the volume of the box
Use the formula V = lwh

3x - 2, 2x + 1, x + 1

A. 6x^3 + x - 2

B. 6x^3 + 5x^2 - 3x - 2

C. 6x^3 - 2

D. 6x^3 - 13x^2 - 3x - 2

Answers

answer is B. detrjrajaetkterjaejq

In the auditorium there are 15 red chairs and 35 blue chairs. What is the ratio of the number of red chairs to the number of blue chairs?

Write your answer as two numbers separated by a colon (for example, 2:3).

Answers

3:7  

This means that for every 7 blue chairs, there are 3 red chairs.

Find the equation of the line that
is parallel to y = 5x – 4 and
contains the point (4,5).

Answers

Answer:

y = 3+1/2

that should be the answer

Omar drew a line that was 12 centimeters long. Which line is 5 centimeters shorter

Answers

Answer:

12 - 5 is 7 so the line would be 7 centimeters

Step-by-step explanation:

Answer:

the answer is 7

Step-by-step explanation:

12-5=7

PLEASE HELP ASAP!!!
Complete this item.
For the following figure, can you conclude that l || m? Select true or false.

Answers

Answer:

d

Step-by-step explanation:

[tex] \qquad \quad\huge \bf༆ Answer ༄[/tex]

The statement is False !

If we observe the two line, we get the results that pair of corresponding angles in the given figure isn't equal. therefore we can conclude that the lines are not parallel

A new ferrari costs 213,054 how much would it cost after a 35% discount?

kinda need help fast

30 points

Answers

Answer:

138485.1

Step-by-step explanation:

35% of 213,054 = 74568.9

213,054 - 74568.9 = 138485.1

How to solve for x using the equation: 12 = -4 (- 6x - 3)

Answers

I don’t know how to explain it so I am just giving the equation

12=-4(-6x-3x)
Divide both sides by 4
12/4=-4(-6x-3x)/4
3=-4(-6x-3x)/4
3=-(-6x-3x)
3=9x
9x/9 = 3/9
Divide both sides by 9
x=1/3

ABCD is a rectangle AB =15 centimeters AC = 25 cm Find The length of BC ​

Answers

Answer:

the answer is explained below (tap on the photo to view it fully)

What is the value of |–3.25| ?

Answers

Answer:

3.25

Step-by-step explanation:

Rule: An absolute value will always be positive.

=> Referring to the rule, the absolute value of |–3.25| is 3.25.

Hoped this helped.

[tex]BrainiacUser1357[/tex]

For any parallelogram what is not always true

Answers

Answer:

The diagonals are congruent.

Step-by-step explanation:

Answer:

1) The diagonals are congruent.

3) The opposite angles are congruent.

4) The opposite sides are parallel.

Step-by-step explanation:Two pairs of opposite sides are congruent. The diagonals are perpendicular to each other. 4 In parallelogram QRST, diagonal is drawn. Which statement must always be true?

if it does not work sorry

Solve for x 18 Х 16 24 0 15 O 12 0 24 o 17​

Answers

Answer:

Look it up

Step-by-step explanation:

What is the area of the triangle?

Answers

Answer: 60 square units

Area of a triangle formula: 1/2 * base * height

So, the height is 10 units and base is 12 units

1/2 * 10 * 12

= 60 square units

show work! my teacher told me this was wrong, what's the correct answer?​

Answers

Answer:

I do not know man but good luck

Which of the expressions below has a product that is greater
than 140? Select all that apply.
A) 11.5 x 12
B) 11.85 x 12
C) 15.2 x 9
D) 23.4 x 6
You can earn 5 coins

Answers

B and D
11.85 x 12 = 142.2
23.4 x 6 = 140.4

Find the value of x and the indicated angles.

Answers

Answer:

x = 19

Indicated angles: 113°

Step-by-step explanation:

We can tell that 6x - 1 is equal to 2x + 75 because they are vertically opposite angles. Now, let's solve.

=> 6x - 1 = 2x + 75=> 6x - 2x = 1 + 75=> 4x = 76=> x = 19

Since we have found the required variable, we can now solve the indicated variables.

Given angles:

6(19) - 12(19) + 75

Let's solve 6(19) - 1 first.

6(19) - 1=> 114 - 1=> 113

Therefore, 6(19) - 1 measures about 108°. Now, let's solve 2(19) + 75

2(19) + 75=> 38 + 75=> 113

We can clearly see that both angles are equal (113 = 113) Because of vertically opposite angles.

Conclusion:

Therefore, the required variable is 'x = 19' and when we substitute the variable in both angles, we find that both angles show 113°.

Hoped this helped.

[tex]BrainiacUser1357[/tex]

Bianca, Kelly, and Sara are running a race. They
complete the race in 2.35 hours. If the race was
51.7 miles, calculate their average speed.
Helppppppppp

Answers

Answer:

22 miles per hour

Step-by-step explanation:

1. Formula: speed = distance/time

2. s = 51.7 mi ÷ 2.35 hrs

3. s = 22 miles per hour

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