How do you multiply #(x-7)(5x^2-3x-5)#?

2 Answers
Jul 23, 2017

Answer:

#5x^3-38x^2+16x+35#

Explanation:

#"each term in the second bracket is multiplied by each "#
#"term in the first bracket, as follows."#

#(color(red)(x-7))(5x^2-3x-5)#

#=color(red)(x)(5x^2-3x-5)color(red)(-7)(5x^2-3x-5)#

#"distributing each bracket gives"#

#=5x^3-3x^2-5x-35x^2+21x+35#

#"collect like terms for simplification"#

#=5x^3-38x^2+16x+35#

Jul 23, 2017

Answer:

#color(green)(5x^3-38x^2+16x+35#

Explanation:

#(x-7)(5x^2-3x-5)#

#:.x xx 5x^2=5x^3#

#:.x xx -3x=-3x^2#

#:.x xx -5=-5x#

#:.-7 xx 5x^2=-35x^2#

#:.-7 xx -3x=21x#

#:.-7 xx -5=35#

#:.=5x^3-3x^2-35x^2-5x+21x+35#

#:.color(green)(=5x^3-38x^2+16x+35#

or:-

#color(white)(aaaaaaaaaaaaa)##5x^2-3x-5#
#color(white)(aaaaaaaaaaa)## xx underline(x-7)#
#color(white)(aaaaaaaaaaaaa)##5x^3-3x^2-5x#
#color(white)(aaaaaaaaaaaaaaaa)##-35x^2+21x+35#
#color(white)(aaaaaaaaaaaaa)##overline(5x^3-38x^2+16x+35)#

#color(white)(aaaaaaaaaaaaa)##color(green)(5x^3-38x^2+16x+35#