A triangle with vertices at $A(-2,2), B(-8,2)$ and $C(-8,-1)$ is reflected about the line $y=2x+1$. Express the coordinates of the reflection of A as an ordered pair.
(A) $(-2,0)$ (B) $(0,-2)$ (C) $(-2,8)$ (D) $(2,-2)$ (E) $(2,0)$.
I know that in the reflection about line $y=x+m$ you do $(x,y)\mapsto(y-m,x+m)$. I don't even know if this is the right one because in this case m will have to be $x+1$ and for me it lead to no where.
Someone please help me if you can.
