How do you divide (2x^3-5x^2+4x+12)/(x-7) 2x35x2+4x+12x7?

2 Answers
Jun 16, 2017

2x^2+9x+67+481/(x-7)2x2+9x+67+481x7

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)(2x^2)(x-7)color(magenta)(+14x^2)-5x^2+4x+122x2(x7)+14x25x2+4x+12

=color(red)(2x^2)(x-7)color(red)(+9x)(x-7)color(magenta)(+63x)+4x+12=2x2(x7)+9x(x7)+63x+4x+12

=color(red)(2x^2)(x-7)color(red)(+9x)(x-7)color(red)(+67)(x-7)color(magenta)(+469)+12=2x2(x7)+9x(x7)+67(x7)+469+12

=color(red)(2x^2)(x-7)color(red)(+9x)(x-7)color(red)(+67)(x-7)+481=2x2(x7)+9x(x7)+67(x7)+481

"quotient "=color(red)(2x^2+9x+67)", remainder "=481quotient =2x2+9x+67, remainder =481

rArr(2x^3-5x^2+4x+12)/(x-7)2x35x2+4x+12x7

=2x^2+9x+67+481/(x-7)=2x2+9x+67+481x7

Jun 16, 2017

color(blue)(2x^2+9x+672x2+9x+67 plus remainder of color(blue)481481

Explanation:

color(white)(.............)ul(color(blue)(2x^2+9x+67)
color(white)(aa)x-7|2x^3-5x^2+4x+12
color(white)(..............)ul(2x^3-14x^3)
color(white)(........................)9x^2+4x
color(white)(........................)ul(9x^2-63x)
color(white)(..............................)67x+12
color(white)(..............................)ul(67x-469)
color(white)(........................................)481