Question 286751
IF you mean:
(x^2+4x-21)/(3+5x-2x^2)
(x+7)(x-3)/(3-x)(1+2x)
(x+7)(x-3)/-(x-3)(-2x-1) cancel out the (x-3) terms.
(x+7)/-(-2x-1)
(x-7)/(2x+1) ans.