A rectangle with the dimensions of 2 feet by 8 feet is similar to a rectangle with the
dimensions of
А 4 feet by 16 feet
B. 6 feet by 12 feet
C 12 feet by 32 feet
D 22 feet by 28 feet

I think it could be no.A 4 feet by 16 feet

y=x+16
y=-x+4

All you have to do is substitute. 
Put the second equation into the first equation.

-x + 4 = x + 16
4 = 2x + 16
-12 = 2x
-6 = x

Now substitute the x into one of the equations to get y.

y = (-6) + 16
y = 10

The solution to these equations is (-6, 10).