Answer: E. 45/4
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Work Shown:
Because we have similar triangles, we can form the proportion below to isolate x.
(AC)/(BC) = (CD)/(AC)
(15)/(20) = (x)/(15)
15*15 = 20x .... cross multiply
225 = 20x
20x = 225
x = 225/20
x = (5*45)/(5*4)
x = 45/4
