4x + y = 8 6y- 9y = 12 which of the options represents the resulting equation after an equivalent expression for y is substituted into the second equation? 4x + 4x - 8 = 8 6(4x - 8) - 9y = 12 6x - 9(-4x + 8) = 12

6x - 9(-4x + 8) = 12

Solving the first eqution for y, you have

... y = -4x +8

Substituting that into the equation

... 6x -9y = 12

you have ...

... 6x -9(-4x +8) = 12 . . . . . . . matches the 3rd choice.

Comment on the question

The given equation is 6y -9y = 12, something entirely different from 6x -9y = 12. None of the answer choices apply to the equations given in your problem statement.

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

their is no graph showing

step-by-step explanation: