How do you factor #40x^3 + 5#?

2 Answers
Jan 1, 2016

Answer:

#5(8x^3+1)#

Explanation:

In the expression #40x^3+5# the only common factor is 5

So we have factored this expression as

#5(8x^3+1)#

Nov 2, 2017

Answer:

#5(2x+1)(4x^2-2x+1)#

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)#