Answer:
x =20
Explanation:
We can use similar triangles and proportions to solve. Take the smaller triangle side on top and the larger triangle side on the bottom.
11 10
---------- = --------------
11+121 10 +5x+10
Combine like terms
11 10
---------- = --------------
132 5x+20
Using cross products
11*(5x+20) = 10*132
55x+220 = 1320
Subtract 220 from each side
55x+220-220 = 1320-220
55x = 1100
Divide by 55
55x/55= 1100/55
x =20