Answer:
x = 9 1/3
Explanation:
We can use the ratios of similar triangles to solve
x 7
----------- = ------------
x+8 13
Using cross products
13x = 7(x+8)
Distribute
13x = 7x+56
Subtract 7x from each side
13x-7x = 7x+56-7x
6x = 56
Divide each side by 6
6x/6 = 56/6
x= 28/3
x = 9 1/3