Question

Solve the system of equations -4x+2y=-6 and -x+8y=21 by combining the equations.

Answer 1

The answer is x equals 3 and y equals 3

Answer 2

x=3 and y=3

Explanation:

−x+8y=21for x:

−x+8y=21

−x+8y+−8y=21+−8y(Add -8y to both sides)

−x=−8y+21

−x

−1

=

−8y+21

−1

(Divide both sides by -1)

x=8y−21

Step: Substitute8y−21forxin−4x+2y=−6:

−4x+2y=−6

−4(8y−21)+2y=−6

−30y+84=−6(Simplify both sides of the equation)

−30y+84+−84=−6+−84(Add -84 to both sides)

−30y=−90

−30y

−30

=

−90

−30

(Divide both sides by -30)

y=3

Step: Substitute3foryinx=8y−21:

x=8y−21

x=(8)(3)−21

x=3(Simplify both sides of the equation)