10 POINTS!! HELP ASAP!! What is the length of AC?

Answer:
D
Step-by-step explanation:
Δ CED and Δ CAB are similar thus the ratios of corresponding sides are equal, that is
[tex]\frac{CE}{CA}[/tex] = [tex]\frac{ED}{AB}[/tex] , substitute values
[tex]\frac{x}{156-x}[/tex] = [tex]\frac{7}{84}[/tex] = [tex]\frac{1}{12}[/tex] ( cross- multiply )
12x = 156 - x ( add x to both sides )
13x = 156 ( divide both sides by 13 )
x = 12
Thus
AC = 156 - x = 156 - 12 = 144 → D
Answer:
D. 144
Step-by-step explanation:
Triangle BAC is similar to triangle DEC, so you can set up a ratio:
[tex]\frac{84}{156-x} = \frac{7}{x}[/tex]
Then cross multiply
84x = 7 (156 - x)
84x = 1092 - 7x
Add 7x to both sides.
91x = 1092
Divide both sides by 91.
x = 12
AC = 156 - x
AC = 156 - 12
AC = 144