SOLUTION: I have a problem with this expression. How would I divide {{5x^3 + 9x^2 + 18x - 4}} by {{5x - 1}}. Also, how could I do similar problems? Thank you

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: I have a problem with this expression. How would I divide {{5x^3 + 9x^2 + 18x - 4}} by {{5x - 1}}. Also, how could I do similar problems? Thank you      Log On


   



Question 36042: I have a problem with this expression. How would I divide
{{5x^3 + 9x^2 + 18x - 4}} by {{5x - 1}}. Also, how could I do similar problems? Thank you

Answer by Prithwis(166) About Me  (Show Source):
You can put this solution on YOUR website!
5x^3 + 9x^2 + 18x - 4
= 5x^3 - x^2 + 10x^2 - 2x + 20x - 4
= x^2(5x-1) + 2x(5x-1) + 4(5x-1)
= (5x-1)(x^2 + 2x + 4)...(1)
When (1) is divided with (5x-1), the result is (x^2 + 2x + 4)
Answer: (x^2 + 2x + 4)
I used a long division approach mentally to determine how I should break the expression in a way so that I can factor them properly.
You may want to use the long division approach, or synthetic division approach to do this kind of division. Please note that the synthetic division works only when you are to divide by a linear expression. There will be instances when you will find a remainder when dividing with a ceratin expression.