Question 302219
factorise 4x^3 - 36x = 4x(x^2 - 9) = 4x(x+3)(x-3)
factorise (2x^2+6x)= 2x(x+3) 

The fraction becomes: 


{{{4x(x+3)(x-3)/2x(x+3) }}}

cancel out "2x" and "x+3"

= 2(x-3)