Answer:
x = 15
Explanation:
Since the triangles are similar then the ratios of corresponding sides are equal, that is
BC/DC = EC/AC , substitute values
3x×5/32 - 5x-5/56 ( cross- multiply )
56(3x - 5) = 32(5x - 5) ← distribute and simplify both sides
168x - 280 = 160x - 160 ( subtract 160x from both sides )
8x - 280 = - 160 ( add 280 to both sides )
8x = 120 ( divide both sides by 8 )
x = 15