Answer: Choice B, AC is 8 units long
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Work Shown:
Given info is AB = 10, AD = 15, AE = 12
Let x = length of AC
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AB/AD = AC/AE
10/15 = x/12 .... substitution
10*12 = 15*x .... cross multiply
120 = 15x
15x = 120
15x/15 = 120/15 .... divide both sides by 15
x = 8
