How do you rewrite 3(x-5)+3x(x-5)3(x5)+3x(x5) as an equivalent product of two binomials?

1 Answer
May 28, 2017

3(x-5)(1+x)3(x5)(1+x)

Explanation:

color(red)(3)(x-5)color(red)(+3x)(x-5)3(x5)+3x(x5)

"take out the "color(blue)"common factor"" of " (x-5)take out the common factor of (x5)

rArr(x-5)(color(red)(3+3x))(x5)(3+3x)

=(x-5)3(1+x)larr" common factor of 3 in " (3+3x)=(x5)3(1+x) common factor of 3 in (3+3x)

=3(x-5)(1+x)=3(x5)(1+x)

"we can check the 2 for equivalence"we can check the 2 for equivalence

3(x-5)+3x(x-5)3(x5)+3x(x5)

=3x-15+3x^2-15x=3x15+3x215x

=3x^2-12x-15larrcolor(blue)" first expansion"=3x212x15 first expansion

"and " 3(x-5)(1+x)larr" expand using FOIL"and 3(x5)(1+x) expand using FOIL

=3(x+x^2-5-5x)=3(x+x255x)

=3(x^2-4x-5)=3(x24x5)

=3x^2-12x-15larrcolor(blue)" second expansion"=3x212x15 second expansion