How do you factor 3x^2 - 2x -21? Algebra Polynomials and Factoring Factoring Completely 1 Answer jk.13 Mar 30, 2018 (3x+7)(x-3) Explanation: 3x^2+7x-9x-21 find two integers that ADD to -2, MULTIPLY to -63 (3*-21) 3x(x-3)+7(x-3) factor out common factor (3x+7)(x-3) Answer link Related questions What is Factoring Completely? How do you know when you have completely factored a polynomial? Which methods of factoring do you use to factor completely? How do you factor completely 2x^2-8? Which method do you use to factor 3x(x-1)+4(x-1) ? What are the factors of 12x^3+12x^2+3x? How do you find the two numbers by using the factoring method, if one number is seven more than... How do you factor 12c^2-75 completely? How do you factor x^6-26x^3-27? How do you factor 100x^2+180x+81? See all questions in Factoring Completely Impact of this question 3938 views around the world You can reuse this answer Creative Commons License