8th math , plwase help

Answer:

yes it is because they are both going by two

Step-by-step explanation:

Answer:

[tex]x = 4[/tex]

[tex]y = -5[/tex]

Step-by-step explanation:

Given

[tex]-10x^2+80x+y=155[/tex]

[tex]5x^2-40x+y=-85[/tex]

Required

Solve by substitution

Make y the subject in [tex]5x^2-40x+y=-85[/tex]

[tex]5x^2-40x+y=-85[/tex]

[tex]y = -5x^2 + 40x - 85[/tex]

Substitute [tex]y = -5x^2 + 40x - 85[/tex] in the first equation

[tex]-10x^2+80x+y=155[/tex]

[tex]-10x^2 + 80x -5x^2 + 40x - 85 = 155[/tex]

Collect Like Terms

[tex]-5x^2-10x^2 + 80x + 40x - 85 - 155=0[/tex]

[tex]-15x^2 + 120x-240=0[/tex]

Divide through by -15

[tex]x^2 -8x + 16 = 0[/tex]

[tex]x^2 - 4x - 4x + 16 = 0[/tex]

[tex]x(x - 4) - 4(x - 4) = 0[/tex]

[tex](x - 4)(x - 4) = 0[/tex]

[tex]x - 4\ = 0[/tex] or [tex]x - 4\ = 0[/tex]

[tex]x = 4[/tex] or [tex]x = 4[/tex]

[tex]x = 4[/tex]

Substitute 4 for x in [tex]y = -5x^2 + 40x - 85[/tex]

[tex]y = -5(4)^2 + 40 * 4 - 85[/tex]

[tex]y = -5*16 + 40 * 4 - 85[/tex]

[tex]y = -80 + 160 - 85[/tex]

[tex]y = -5[/tex]

Answer:

-2.5

Step-by-step explanation:

Answer:

d

Step-by-step explanation:

If chord BC passes through the centre then it is a diameter . then

∠ BAC is the angle in a semicircle and x = 90°

y = 180° - (90 + 25) ← angle sum in a triangle

y = 180° - 115° = 65°

Thus

x = 90°, y = 65° → d

In this exercise we have to use the knowledge of triangles inscribed in a circle, in this way it will be possible to calculate the angles, then:

Letter D

Knowing that it is a triangle inscribed in a circle, in this way we can describe it as:

So:

[tex]y = 180 - 115 = 65\\ x = 90\\ y = 65 [/tex]

See more about triangles at brainly.com/question/25813512

Answer:

-19a^6 -7

are you asking to simplify??

SSA

Step-by-step explanation:

put name of triangle abc are same

Answer:

y = -3x - 2

Step-by-step explanation:

slope (m) = (-8 - -5) / (2 - 1)   ... difference of y/difference of x

m = -3

y = mx + b

y = -3x + b

for (3,-11)    b = y + 3x = -11 + 3x3 = -2

equation: y = -3x - 2

Answer:

Answer in photo

Step-by-step explanation:

Answer:

A direct variation is when x and y (or f(x) and x) are directly proportional to each other... For example, if you have a chart that says x and y, and in the x column is 1, 2 and 3, and the y column says 2, 4 and 6... then you know it's proportional because for each x, y increases by 2

Step-by-step explanation:

Answer:

I think this should be your answer look at attachment

Step-by-step explanation:

hope this helps

The graph of the given situation is required.

The required graph is attached.

Let x be the cost of each seat

and y be the cost of additional snack.

Cost of seat = $20

Cost of snack = $5

Total cost = $400

The linear equation will be

[tex]20x+5y=400[/tex]

Finding two points

[tex]x=0[/tex]

[tex]5y=400\\\Rightarrow y=\dfrac{400}{5}=80[/tex]

[tex](0,80)[/tex]

[tex]y=0[/tex]

[tex]20x=400\\\Rightarrow x=\dfrac{400}{20}\\\Rightarrow x=20[/tex]

[tex](20,0)[/tex]

Join the points and the graph representing the situation is obtained.

Learn more:

https://brainly.com/question/14268805

https://brainly.com/question/7744405

Answer:

$231,000

Step-by-step explanation:

$110 times 2,100 is $231,000

Answer:

add pic pls ok?

Step-by-step explanation:

Answer:

Its B 12x^18

Step-by-step explanation:

Answer:

the equation to use would be D (255-20(5) = ?). To solve, first multiply 20 and 5 and you would get 100 so the equation would be 255 - 100 = ? Then you would subtract 100 from the 255 to get $155 left. To solve for 7 weeks you would replace the 5 in the equation with 7 so your equation would be 255 - 20(7) = ? Next you would multiply 20 and 7 to get 140. the equation would then be 255 - 140 = ? Subtract 140 from 255 and you would get 115. So after 7 weeks she would have $115 left in her account.

Answer:

The slope is 2

Step-by-step explanation:

Given

x   y

2    3

5    9

Required

Determine the slope

First, we have:

[tex](x_1,y_1) = (2,3)[/tex]

[tex](x_2,y_2) = (5,9)[/tex]

The slope is then calculated as:

[tex]m = \frac{y_2 - y_1}{x_2 - x_1}[/tex]

This gives:

[tex]m = \frac{9-3}{5-2}[/tex]

[tex]m = \frac{6}{3}[/tex]

[tex]m =2[/tex]

Hence, the slope is 2.

Answer:

C

Step-by-step explanation:

Answer:

Step-by-step explanation:

I just got this correct on the test

The linear relationship between c and s is c = 20s and on the graph paper, it will be a line.

It is defined as the relationship between two variables when the first variable increases, the second variable also increases according to the constant factor.

We have:

Mrs. Robertson is preparing manipulatives for her math class. Each student will receive a plastic cup with 20 two-color counters.

c is the total number of two-color counters

s is the number of students

The linear relationship becomes:

c = 20s

Thus, the linear relationship between c and s is c = 20s and on the graph paper, it will be a line.

Learn more about the proportional here:

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#SPJ5

Answer:

20 + 8 =28

Step-by-step explanation:

Step-by-step explanation:

To find the reciprocal, divide 1 by the number given. Simplify. Multiply the numerator by the reciprocal of the denominator. Multiply 65 6 5 by 1 1 .

Answer:

n < - 3 or n > - 2

Step-by-step explanation:

Inequalities of the type | x | > a , have solutions of the form

x < - a or x > a

Then

2n + 5 < - 1 or 2n + 5 > 1

Solve both inequalities

2n + 5 < - 1 ( subtract 5 from both sides )

2n < - 6 ( divide both sides by 2 )

n < - 3

OR

2n + 5 > 1 ( subtract 5 from both sides )

2n > - 4 ( divide both sides by 2 )

n > - 2

Solution is n < - 3 or n > - 2

Answer:

c) x=4

Step-by-step explanation:

Answer:

790

Step-by-step explanation:

19 3/4÷ 1/8=158

158*5 = 790

  Volume of a cone =  (1/3) pi x r^2 x h

Volume of a cylinder =  pi x r^2 x h

Volume of the cylinder = pi x 2^2 x 3 = 37.68 cubic inches

Now set the volume for the cone to the volume of the cylinder and solve for the height.

37.68 = (1/3) x pi x r^2 x h

37.68 = (1/3) x pi x 3^2 x h

37.68 = (1/3) x pi x 9 x h

37.68 = 9.42 x h

h = 37.68 / 9.42

h = 4

The height of the cone is 4 cm.

[tex]x \: and \: y[/tex]

hope my answer is helpful to you

plz mark me as brainlist

Step-by-step explanation:

[tex]circumference \: of \: the \: circle = 2\pi \times \frac{diameter}{2} \\= 2\pi \times radius = 2 \times \pi \times \frac{1}{2} = \pi = 3.14 \: cm[/tex]

Answer:

5.5, 4.333 or 13/3

Step-by-step explanation:

Use substitution method.

Answer:

(5.5, 4.3 )

Step-by-step explanation:

Given the 2 equations

4x - 15y = - 43 → (1)

2x - 3y = - 2 → (2)

Multiplying (2) by - 2 and adding to (1) eliminates the term in x

- 4x + 6y = 4 → (3)

Add (1) and (3) term by term to eliminate x, that is

- 9y = - 39 ( divide both sides by - 9 )

y = [tex]\frac{39}{9}[/tex] ≈ 4.3 ( to 1 dec. place )

Substitute this value into either of the 2 equations and solve for x

Substituting into (2)

2x - 3([tex]\frac{39}{9}[/tex] ) = - 2

2x - 13 = - 2 ( add 13 to both sides )

2x = 11 ( divide both sides by 2 )

x = 5.5

Best solution is (5.5, 4.3 )

Answer:

A. 2x+6 .  B. 10x-20        C. 8x+4         D. 6x-24y

Step-by-step explanation: