Triangle abc has vertices a(5, 3) , b(3, 7) , and c(1, 4) . triangle abc is dilated, and the vertices of the image are a′(7.5, 4.5) , b′(4.5, 10.5) , and c' (1.5,6). the center of dilation is the origin. a. 1/2 b.2/3 c3/2 d2

First, we have the following points:
 A (5, 3)
 B (3, 7)
 C (1, 4)
 We multiply these vertices by a factor k to obtain the new vertices:
 A '(k * 5, k * 3) = (7.5, 4.5)
 B '(k * 3, k * 7) = (4.5, 10.5)
 C '(k * 1, k * 4) = (1.5.6)

 We note that the value of k is:
 k = 3/2

 
 C3 / 2