How do you rewrite 3(x-5)+3x(x-5)3(x−5)+3x(x−5) as an equivalent product of two binomials?
1 Answer
May 28, 2017
Explanation:
color(red)(3)(x-5)color(red)(+3x)(x-5)3(x−5)+3x(x−5)
"take out the "color(blue)"common factor"" of " (x-5)take out the common factor of (x−5)
rArr(x-5)(color(red)(3+3x))⇒(x−5)(3+3x)
=(x-5)3(1+x)larr" common factor of 3 in " (3+3x)=(x−5)3(1+x)← common factor of 3 in (3+3x)
=3(x-5)(1+x)=3(x−5)(1+x)
"we can check the 2 for equivalence"we can check the 2 for equivalence
3(x-5)+3x(x-5)3(x−5)+3x(x−5)
=3x-15+3x^2-15x=3x−15+3x2−15x
=3x^2-12x-15larrcolor(blue)" first expansion"=3x2−12x−15← first expansion
"and " 3(x-5)(1+x)larr" expand using FOIL"and 3(x−5)(1+x)← expand using FOIL
=3(x+x^2-5-5x)=3(x+x2−5−5x)
=3(x^2-4x-5)=3(x2−4x−5)
=3x^2-12x-15larrcolor(blue)" second expansion"=3x2−12x−15← second expansion