A size transformation with a center of Q(1, -1) maps B (3,-7) B' (7, -19). Find the scale factor. Show work.

Question

Not sure how to approach this problem

Answer 1

Distance from Q to B is √40.

Distance from Q to B' is √360

The scale factor is √360 / √40, or 3.

Answer 2

The key here is accounting for the center not being (0,0). Subtract the center point (1,-1) from B and B' (Bx-1, Bx+1). Then you can take the adjusted B'/B to find the scale factor. Both the the x and y values will have to give the same number.