How do you factor #40x^3 + 5#?
2 Answers
Jan 1, 2016
Explanation:
In the expression
So we have factored this expression as
Nov 2, 2017
Explanation:
#"take out a "color(blue)"common factor of 5"#
#rArr40x^3+5#
#=5(8x^3+1)#
#8x^3+1" is a "color(blue)"sum of cubes"#
#•color(white)(x)a^3+b^3=(a+b)(a^2-ab+b^2)#
#"note that "8x^3=(2x)^3" and "1=1^3#
#"here "a=2x" and "b=1#
#rArr8x^3+1=(2x+1)((2x)^2-(2x.1)+1^2)#
#color(white)(rArr8x^3+1)=(2x+1)(4x^2-2x+1)#
#rArr40x^3+5=5(2x+1)(4x^2-2x+1)#