Question 620893
-x^2 + 10x - 21/-3x^2 + 23x - 14


First we need to factor what we can.


-1(x^2 -10x +21)/-1(3x^2 -23x +14)
-1(x - 7)(x - 3)/-1(3x - 2)(x - 7)


The -1's and (x - 7)'s cancel out leaving the following:


(x - 3)/(3x - 2) 

That is your final answer.