How do you multiply 3x(x+9)? Algebra Polynomials and Factoring Multiplication of Monomials by Polynomials 1 Answer Don't Memorise Jun 25, 2015 = color(green)(3x^2 + 27x Explanation: color(green)( 3x)(x+9) Here color(green)(3x) needs to be multiplied with each term within brackets: = color(green)(3x) . (x) + color(green)(3x) . (9) = color(green)(3x^2 + 27x Answer link Related questions What is Multiplication of Monomials by Polynomials? How do you multiply monomials by polynomials? How do you multiply monomials by monomials? How do you multiply (3xy^5)(-6x^4y^2)? How do you multiply and simplify 6ab(-10a^2 b^3+c^5)? How do you simplify -3a^2b(9a^2-4b^2)? How do you multiply y(xy^4)? How do you multiply (2x-1)(x^3-2x^2+3x-4)? How do you multiply (5n^2)(2n^5 - 2n^3 3n^7)? How do you simplify 2t^2+(3+5)(4t)? See all questions in Multiplication of Monomials by Polynomials Impact of this question 2820 views around the world You can reuse this answer Creative Commons License