How do you divide (5x^4-3x^3+2x^2-1)div(x^2+4)(5x43x3+2x21)÷(x2+4) using long division?

1 Answer
Feb 3, 2017

The answer is =(5x^2-3x-18)+(12x+71)/(x^2+4)=(5x23x18)+12x+71x2+4

Explanation:

Let's do the long division

color(white)(aaaa)aaaa5x^4-3x^3+2x^2-15x43x3+2x21color(white)(aaaaaaaa)aaaaaaaa|x^2+4x2+4

color(white)(aaaa)aaaa5x^45x4color(white)(aa aaaa)aaaaaa+20x^2+20x2color(white)(aaaaaaaaaaa)aaaaaaaaaaa|5x^2-3x-185x23x18

color(white)(aaaa)aaaa0-3x^303x3color(white)(aa a)aaa-18x^218x2color(white)(aaaaaaa)aaaaaaa

color(white)(aaaaaa)aaaaaa-3x^33x3color(white)(aaaa)aaaa-18x^2-12x-118x212x1color(white)(aaaaaaa)aaaaaaa

color(white)(aaaaaaaa)aaaaaaaa00color(white)(aaaaa)aaaaa-18x^2-12x18x212xcolor(white)(a)a-7272

color(white)(aaaaaaaaaaaaaaaaa)aaaaaaaaaaaaaaaaa00color(white)(aaa)aaa+12x+12xcolor(white)(aa)aa+71+71

Therefore,

(5x^4-3x^3+2x^2-1)/(x^2+4)=5x^2-3x-18+(12x+71)/(x^2+4)5x43x3+2x21x2+4=5x23x18+12x+71x2+4

The quotient is =5x^2-3x-18=5x23x18

The remainder is =12x+71=12x+71