How do you simplify #(2+i)(1+2i)(3-4i)#? Precalculus Complex Numbers in Trigonometric Form Multiplication of Complex Numbers 1 Answer VinÃcius Ferraz Mar 20, 2017 #15i + 20# Explanation: #(2 + 4i +i +2i^2)(3 - 4i)# #= 5i*3 - 5i * 4i# Answer link Related questions How do I multiply complex numbers? How do I multiply complex numbers in polar form? What is the formula for multiplying complex numbers in trigonometric form? How do I use the modulus and argument to square #(1+i)#? What is the geometric interpretation of multiplying two complex numbers? What is the product of #3+2i# and #1+7i#? How do I use DeMoivre's theorem to solve #z^3-1=0#? How do I find the product of two imaginary numbers? How do you simplify #(2+4i)(2-4i)#? How do you multiply #(-2-8i)(6+7i)#? See all questions in Multiplication of Complex Numbers Impact of this question 2671 views around the world You can reuse this answer Creative Commons License