Polygon WXYZ has vertices W(4, 2), X(6, 4), Y(2, 3), and Z(4, 5). If W′X′Y′Z′ is a dilation of WXYZ with center of dilation (0, 0) and vertex coordinates W′(2, 1), X′(3, 2), Y′(1, 1.5), and Z′(2, 2.5), find the scale factor.

(0,0) is the origin of a graph, so both W and W' remain at the origin.

The other 3 vertices double in size:

If you multiply all the numbers in X, Y and Z by 2, they become the numbers in X', Y' and Z'.

X(1,2)  x 2 = (1*2,2*2) = X'(2,4)

Y(4,2) x 2 = (4*2, 2*2) = Y'(8,4)

Z(3,0) x 2 = (3*2, 0*2) = Z'(6,0)

That means the scale factor is 2

- both graphs increase on their domain.

- the graphs of both functions have the same x-intercept.

- neither graph has a y-intercept.