(-1,2) lies on y=f(x) and undergoes a vertical and horizontal stretch. point on a transformed function is (-4,1) , the vertical stretch is ?
Perhaps I do not understand the question correctly, but it seems to me that the answer is very simple.
The y coordinate changes by 1-2 = -1 and the x coordinate changes by -4--1 = -3
Therefore to me it seems like the vertical stretch is -1
+154 
