Question 107083
X^2 - 3x – 10/5x * 15x^2/3x- 15

{{{x^2-3x-10}}} factorises to (x-5)(x+2)

3x-15 factorises to 3(x-5)

now we have 
{{{((x-5)(x+2))/5x}}} times {{{15x^2/(3(x-5))}}}

which is 

{{{((x-5)(x+2)(15x^2))/(15x(x-5))}}}
the 15 cancels as does the x-5, and the x from the denominator cancells with the x^2 to leave just an x on the numerator

the answer is 

{{{(x+2)x}}} as all the denominator disappears witht he cancelling