Question 30690
The question must be
5x^2+10x over x^2-x-6 divided by 15x^3+45x^2 over x^2-9

[(5x^2+10x)/ (x^2-x-6)] divided by [(15x^3+45x^2)/(x^2-9)]
=[5x(x+2)/(x-3)(x+2)]divided by [15x^2(x+3)/(x+3)(x-3)](factoring)
=[5x/(x-3)]divided by [15x^2/(x-3)] 
(cancelling (x+2) in the first fraction and (x+3) in the second)
=[5x/(x-3)]X[(x-3)/15x^2] 
(replacing the division sign by multiplication sign is followed by writing the fraction after the division sign now as (1/that fraction)
=1/3x (cancelling 5x(x-3))

Request: Put down horizontal line for division and verify