How do you multiply #(7x+3) (7x+3)#? Algebra Polynomials and Factoring Multiplication of Polynomials by Binomials 1 Answer Meave60 Aug 21, 2015 #(7x+3)(7x+3)=(7x+3)^2=49x^2+42x+9# Explanation: #(7x+3)(7x+3)=(7x+3)^2# #(7x+3)^2# is the square of a sum with the form #(a+b)^2=a^2+2ab+b^2#, where #a=7x# and #b=3#. #(7x+3)^2=(7x)^2+(2*7x*3)+(3)^2##=# #(7x+3)^2=49x^2+42x+9# You could also use the FOIL method. #(7x+3)(7x+3)=(7x*7x)+(7x*3)+(3*7x)+(3*3)##=# #(7x+3)(7x+3)=49x^2+21x+21x+9##=# #(7x+3)(7x+3)=49x^2+42x+9# Answer link Related questions What is FOIL? How do you use the distributive property when you multiply polynomials? How do you multiply #(x-2)(x+3)#? How do you simplify #(-4xy)(2x^4 yz^3 -y^4 z^9)#? How do you multiply #(3m+1)(m-4)(m+5)#? How do you find the volume of a prism if the width is x, height is #2x-1# and the length if #3x+4#? How do you multiply #(a^2+2)(3a^2-4)#? How do you simplify #(x – 8)(x + 5)#? How do you simplify #(p-1)^2#? How do you simplify #(3x+2y)^2#? See all questions in Multiplication of Polynomials by Binomials Impact of this question 1385 views around the world You can reuse this answer Creative Commons License