Solving systems by substitution y=-7x

First, we can substitute the value of y from the first equation into the second equation:

2x + 8(-7x - 16) = -20
2x - 56x - 128 = -20
-54x - 128 = -20

Now, we can solve for x:

-54x = -108
x = 2

Now that we have the value of x, we can substitute it back into the first equation to solve for y:

y = -7(2) - 16
y = -14 - 16
y = -30

Therefore, the solution to the system of equations is x = 2 and y = -30.

-20+ 128

-20 + 128 = 108

-8 + 15

-8 + 15 = 7

-1 + 3

-1 + 3 = 2