Explanation:
BE/BC=BD/BA
tHE TWO SIMILAR TRIANGLES ARE BED AND BC. tHE PROPORTION ABOVE REPRESENTS USE OF THE TWO SIMILAR TRIANGLES.
4/(4 + 10) = 5/(5+X) Cross Multiply
4(5+x) = 5(4+10)m
20 +4x=20 +50 subtract 20 from both sides
4x = 50 divide by 4
x =12.5