# Thread: dividing a polynomial by a polynomial

1. ## dividing a polynomial by a polynomial

i understand that i have to estimate but i am stuck on this one.

(2u^3 - 13u^2 - 8) /(7 - u)

2. How would we know you understood/understand any of the answers given you so far?

I will answer this one, but it will be my last---unless you say you understand or not, or you can follow or not, the answer.

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(2u^3 - 13u^2 - 8) /(7 - u)

1) One way is try to factor the numerator to see if the denominator is one of the factors. If the denominator is a factor of the numerator, then that factor and the denominator cancels each other. What remains is the answer.

In the example, the 7 of the denominator is not a whole-number factor of the 8 of the numerator, so it is not easy to factor the numerator to see if (7-u) or (u-7) will show up.

2) Another way is by long division.
(2u^3 - 13u^2 - 8) /(7 - u)
= (2u^3 - 13u^2 - 8) /(-u +7)
I cannot show the long division here, but if you know how to do it, then do it on paper there.
You should get:
= -2u^2 -u -7, remainder 41. ---------answer.