Solve the given Nonlinear System (confused how)

y=4x-x^2+8
y=x^2-2x

I'm not sure what to do, my substitution is not giving me the correct answer. I need help bad.

they give you two equations for y, replace the y in one with the right hand side of the other.
for example:
x^2-2x=4x-x^2+8

now just solve for x
put your answer(s) into one of the two equations to get the associated y value(s).

Let me know if you have any other questions.