algebra
posted by Christi .
solve the following using substitution
8x4y=16
y=2x4
8x4(2x4)=16
8x8x+16=16
0x+16=16
so what do i do now?

Those two equations are the same.
Look at your first equation dividing both sides by 4
2 x  y = 4 or y = 2x4 which is the second equation exactly. There is no intersection of a line with itself in a point. The system of two equations given has no solution. 
Thank you that is what I thought but wasn't sure when I did not come up with an answer.

uyg