Question

If (x, y) is a solution to the system of equations, what is the value of y?

x + 1/8y = 20
x + 1/4y = 4

Answer 1

X+1/8y=20
X+2/8y=4 (converted the fraction so also has denominator 8)

Subtract the first from the second equation

1/8y=-16
Y=-128

Plug in to get x and check it.
X+1/8(-128)=20
X-16=20
X=36

Check with second equation.
X+1/4(-128)=4
X-32=4
X=36

So y= -128