How do you factor the expression #3x^2 + 15x -42#? Algebra Polynomials and Factoring Factorization of Quadratic Expressions 1 Answer Shubh Apr 5, 2018 Factors are: #(x+7)(3x-6)# Explanation: By middle term splitting, #3x^2+15x-42=0# #3x^2+21x-6x-42=0# #3x(x+7)-6(x+7)=0# #(x+7)(3x-6)=0# #x=-7# or,#x=2# Answer link Related questions How do you factor trinomials? What is factorization of quadratic expressions? How do you factor quadratic equations with a coefficient? What are some examples of factoring quadratic expressions? How do you check that you factored a quadratic correctly? How do you factor #x^2+16x+48#? How do you factor #x^2-9x+20#? Question #3fdac How do you factor #8+z^6#? There is no GCF to be factor out, so is there another method to complete this? How do you factor #2t^2+7t+3#? See all questions in Factorization of Quadratic Expressions Impact of this question 4661 views around the world You can reuse this answer Creative Commons License