How do you simplify \frac { x ^ { 3} + 5x ^ { 2} - 5x + 8} { x - 3}x3+5x25x+8x3?

2 Answers
Feb 22, 2018

Use long division to factorise the numerator

Explanation:

Using long division, we divide the numerator by the denominator to give ourselves a quadratic and a remainder.

(x^3+5x^2-5x)/(x-3) =(x^2+8x+19)+65/(x-3)x3+5x25xx3=(x2+8x+19)+65x3

Feb 22, 2018

x^2+8x+19+65/(x-3)x2+8x+19+65x3

Explanation:

"one way is to use the divisor as a factor in the numerator"one way is to use the divisor as a factor in the numerator

"consider the numerator"consider the numerator

color(red)(x^2)(x-3)color(magenta)(+3x^2)+5x^2-5x+8x2(x3)+3x2+5x25x+8

=color(red)(x^2)(x-3)color(red)(+8x)(x-3)color(magenta)(+24x)-5x+8=x2(x3)+8x(x3)+24x5x+8

=color(red)(x^2)(x-3)color(red)(+8x)(x-3)color(red)(+19)(x-3)color(magenta)(+57)+8=x2(x3)+8x(x3)+19(x3)+57+8

=color(red)(x^2)(x-3)color(red)(+8x)(x-3)color(red)(+19)(x-3)+65=x2(x3)+8x(x3)+19(x3)+65

"quotient "=color(red)(x^2+8x+19)," remainder "=65quotient =x2+8x+19, remainder =65

>rArr(x^3+5x^2-5x+8)/(x-3)>x3+5x25x+8x3

=x^2+8x+19+65/(x-3)=x2+8x+19+65x3