The small triangle is 1/2 the size of the larger one ( comparing like sides 5 is 1/2 of 10).
This means AC is 1/2LN.
So you have:
x +5 = 1/2(3x +3)
Simplify:
x+5 = 1.5x +1.5
Subtract 1.5x from each side:
-.5x +5 = 1.5
Subtract 5 from each side:
-.5x = -3.5
Divide both sides by -.5:
x = -3.5 / -.5
x = 7
Now you have x.
AC = x +5 = 7+5 = 12
The answer is G.
