How do you factor #y= 3x^3 + 81 # ? Algebra Polynomials and Factoring Monomial Factors of Polynomials 1 Answer Ujjwal Mar 6, 2018 #y=3(x+3)(x^2+9-3x)# Explanation: #y=3x^3+81# #=>y=3(x^3+27)# #=>y=3(x^3+3^3)# #a^3+b^3=(a+b)(a^2+b^2-ab)# So , #y=3(x^3+3^3)# #=> y=3(x+3)(x^2+3^2-x xx 3)# #=> y=3(x+3)(x^2+9-3x)# Answer link Related questions What are Monomial Factors of Polynomials? How do you factor polynomials by finding the greatest common factor? How can a factoring problem be checked? How do you find the greatest common factors of variable expressions? How do you factor #3a+9b+6#? What is the greatest common factor of #a^3-3a^2+4a#? How do you factor #12xy+24xy^2+36xy^3#? How do you find the greatest common factor of #45y^{12}+30y^{10}#? How do you factor #92x^10y^4 - 54x^12y^9#? How do you factor #4x^2+x#? See all questions in Monomial Factors of Polynomials Impact of this question 2390 views around the world You can reuse this answer Creative Commons License