Question 7261
Is your problem: {{{(r+5)/(r^2+5r-14)}}}/{{{(r^2+4r-21)/(2-2)}}}

or is your problem: {{{(r+5)/(r^2+5r-14)}}}/{{{(2-2)/(r^2+4r-21)}}}


Assuming that your problem is {{{(r+5)/(r^2+5r-14)}}}/{{{(2-2)/(r^2+4r-21)}}}, 
Change it from division to multiplication:
{{{(r+5)/(r^2+5r-14)}}}*{{{(r^2+4r-21)/(2-2)}}}


Factorize
{{{(r+5)/(r+7)(r-2)}}}*{{{(r+7)(r-3)/(2-2)}}}


(r+7) cancels out


{{{(r+5)(r-3)/(r-2)(1)}}}


{{{(r^2+2r-5)/(r-2)}}}