Answer:
x = 33
Explanation:
Because the parallel lines are intersected by two transversals, some parts of this figure correspond to each other. In order to solve this problem, you need to identify which sides correlate (you can tell they correlate because of the AAA property; if you extend the lines, a triangle with 2 parallel lines intersecting it would be formed, so you would see the three triangles are similar):
9 corresponds to 12
x corresponds to (x + 11)
Now, you need to find the scale factor by dividing 12 by 9:
12 ÷ 9 = 4/3
Since you know the scale factor is 4/3, you can now write and solve an equation:
4/3x = x + 11 (given)
1/3x = 11 (subtract x from both sides)
x = 33 (multiply both sides by 3)