How do you multiply #(-3+5i)(-5+7i)#? Precalculus Complex Numbers in Trigonometric Form Multiplication of Complex Numbers 1 Answer Steve M Jan 11, 2017 # (-3+5i)(-5+7i) = -20-46i# Explanation: Multiplying out the brackets term by term gives: # (-3+5i)(-5+7i) # # \ \ \ \ \ = (-3)(-5) + (-3)(7i) + (5i)(-5)+(5i)(7i)# # \ \ \ \ \ = 15-21i-25i+35i^2# # \ \ \ \ \ = 15-46i+35i^2# # \ \ \ \ \ = 15-46i-35 " " (because i^2=-1)# # \ \ \ \ \ = -20-46i# 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 3491 views around the world You can reuse this answer Creative Commons License