How do you divide (x^3-10x^2+30x+3)/(x-5)x310x2+30x+3x5?

1 Answer
Nov 14, 2015

Use long division or synthetic division.

Explanation:

![http://calc101.com/webMathematica/long-divide.jsp

First step: Realize that xx needs to be multiplied by x^2x2 in order to be the x^3x3 in x^3-10x^2+30x+3x310x2+30x+3. Then, multiply the x^2x2 throughout x-5x5 to get x^3-5x^2x35x2 and SUBTRACT it (remember, the signs will change) from x^3-10x^2+30x+3x310x2+30x+3.

You are left with -5x^2+30x+35x2+30x+3, but only the first term is important for now. Like you did with the x^3x3 in the first step, realize that you will need to add a -5x5x on top so that the x(-5x)=-5x^2x(5x)=5x2. Continue multiplying and subtracting until you get to 28, which is the remainder.

All together, the answer would be written as:
color(blue)(x^2-5x+5+28/(x-5)x25x+5+28x5