Question

The pre-image of a shape contains the point E(5, -10). After a dilation, the corresponding image point is E'(1, -2). What was the scale factor used?

Answer 1

Assuming the dilation is centered at the origin, the scale factor k satisfies (1, -2) = k(5, -10). So

k = 1/5 = 0.2

(check: -2 = (1/5)(-10)).