Answer:
A
Step-by-step explanation:
Set up a ratio for the two triangles that are there.
x/(x + 10) = 20 / (20 + 8) Combine the two terms in the right denominator
x/(x + 10) = 20/28 Cross Multiply
28x = 20(x + 10) Remove the brackets on the right
28x = 20 x + 200 Subtract 20x from both sides
8x = 200 Divide by 8
x = 200 /8
x = 25