How do you factor #27x^3+8y^3#?

3 Answers
May 15, 2018

#(3x+2y)(9x^2-6xy+4y^2)#

Explanation:

#27x^3+8y^3#

=#(3x)^3+(2y)^3#

=#(3x+2y)((3x)^2-(3x)(2y)+(2y)^2)#

=#(3x+2y)(9x^2-6xy+4y^2)#

May 15, 2018

#(3x+2y)(9x^2-6xy+4y^2)#

Explanation:

Apply the rule #(a^3+b^3)=(a+b)(a^2-ab+b^2)#

May 15, 2018

#(3x+2y)(9x^2-6xy+4y^2)#

Explanation:

#"this is a "color(blue)"sum of cubes"#

#"which factors in general as"#

#•color(white)(x)a^3+b^3=(a+b)(a^2-ab+b^2)#

#27x^3=(3x)^3rArra=3x#

#8y^3=(2y)^3rArrb=2y#

#rArr27x^3+8y^3=(3x+2y)((3x)^2-(3x xx2y)+(2y)^2)#

#color(white)(xxxxxxxxxx)=(3x+2y)(9x^2-6xy+4y^2)#