How do you factor the expression #125b^3+27#?

1 Answer
May 22, 2018

Answer:

#(5b+3)(25b^2-15b+9)#

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)#

#125b^3=(5b)^3rArra=5b#

#27=(3)^3rArrb=3#

#rArr125b^3+27=(5b+3)((5b)^2-(5bxx3)+3^2)#

#color(white)(raArr125b^3+27)=(5b+3)(25b^2-15b+9)#