SOLUTION: I am dividing Rational expression by another rational expression and am getting stuck. Here is the situation: the problem: x^2+3x-28/x^2-36 divided by x^2-13x+36/x^2+11x+30 Aft

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons -> SOLUTION: I am dividing Rational expression by another rational expression and am getting stuck. Here is the situation: the problem: x^2+3x-28/x^2-36 divided by x^2-13x+36/x^2+11x+30 Aft      Log On


   



Question 971728: I am dividing Rational expression by another rational expression and am getting stuck. Here is the situation:
the problem: x^2+3x-28/x^2-36 divided by x^2-13x+36/x^2+11x+30
After inverting the dividend, I followed the steps and ended up with
(x-7)(x-4)/(x-9)(x+4) times (x+6)(x+5)/(x-9)(x-4)
After cancelling out (x-4), I'm stuck.
The answer key has an answer of
(x-7)(x+5)/(x-6)(x-9) How did they get that answer if there is still (x+5) and (x+4) still in the equation?

Found 2 solutions by Boreal, MathTherapy:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
x^2+3x-28/x^2-36 ;; This is (x+7) (x-4)/(x+6)(x-6)
x^2-13x+36/x^2+11x+30 ;; This is (x-9)(x-4)/(x+6)(x+5)
Numerator
(x+7) (x-4)/(x+6)(x-6) * (x+6)(x+5)/(x-4)(x-9)
The (x+6) go away and so do the (x-4)
(x+7)/(x-6) * (x+5)/(x+9)
You can cancel an (x+6); also, the first term in the numerator is (x+7), not (x-7)

Answer by MathTherapy(10551) About Me  (Show Source):
You can put this solution on YOUR website!

I am dividing Rational expression by another rational expression and am getting stuck. Here is the situation:
the problem: x^2+3x-28/x^2-36 divided by x^2-13x+36/x^2+11x+30
After inverting the dividend, I followed the steps and ended up with
(x-7)(x-4)/(x-9)(x+4) times (x+6)(x+5)/(x-9)(x-4)
After cancelling out (x-4), I'm stuck.
The answer key has an answer of
(x-7)(x+5)/(x-6)(x-9) How did they get that answer if there is still (x+5) and (x+4) still in the equation?
This is how:
%28x%5E2+%2B+3x+-+28%29%2F%28x%5E2+-+36%29%22%F7%22%28x%5E2+-+13x+%2B+36%29%2F%28x%5E2+%2B+11x+%2B+30%29
%28x+%2B+7%29%28x+-+4%29%2F%28x+-+6%29%28x+%2B+6%29%22%F7%22%28x+-+9%29%28x+-+4%29%2F%28x+%2B+5%29%28x+%2B+6%29 ------ Factoring numerators and denominators
%28x+%2B+7%29%28x+-+4%29%2F%28x+-+6%29%28x+%2B+6%29%22%2A%22%28x+%2B+5%29%28x+%2B+6%29%2F%28x+-+9%29%28x+-+4%29 ------ Changing division to multiplication and inverting DIVISOR
%28x+%2B+7%29cross%28%28x+-+4%29%29%2F%28x+-+6%29cross%28%28x+%2B+6%29%29%22%2A%22%28x+%2B+5%29cross%28%28x+%2B+6%29%29%2F%28x+-+9%29cross%28%28x+-+4%29%29 ----- Canceling numerators and denominators
%28%28x+%2B+7%29%28x+%2B+5%29%29%2F%28%28x+-+6%29%28x+-+9%29%29, or
You should be able to determine where you went wrong!!