Question

Use the subsitution method to solve the system of equations. y=-4x 8x-y=6

Answer 1

`y=-4x \\8x-y=6\\\\8x-(-4x)=6\\8x+4x=6\\12x=6\\x=(6)/(12)=(1)/(2)\\\\y=-4\cdot(1)/(2)\\y=-2`

Answer 2

We can substitute y in the second equation for -4x.

8x-(-4x)=6

8x+4x=6

12x=6

X=0.5 or 1/2

To solve for y substitute x for 1/2 in the first or second equation. Substituting it into the first equation is easier.

Y=-4(1/2)

Y=-2

To check substitute x and y for 1/2 and -2.