Answer:
x = 4
Step-by-step explanation:
ΔABC ≈ ΔDBE
set up a proportion of corresponding sides:
BD / BE = BA / BC
BA = 10 - x + x = 10
10-x / 3 = 10 / 5
cross-multiply:
5(10 - x) = 3(10)
50 - 5x = 30
-5x = -20
