Simplify fully: (7x^2 - 21x)/(x^2 + 2x - 15)

This one is quite complicated to answer typed up like this and i would definitley use a white board Show that 7x^2 - 21x can be come x(7x-21) which can in turn become 7x(x-3) Show that x^2 + 2x - 15 can become (x+5)(x-3) since 5x-3=-15 5+-3=+2 Show that [7x(x-3)]/[(x+5)(x-3)] (x-3) then can cancel out to become 7x/(x+5)