How do you simplify #(-1+4i)(-1-4i)#? Precalculus Complex Numbers in Trigonometric Form Complex Number Plane 1 Answer J'Neal · Stefan V. Apr 10, 2017 #17# Explanation: FOIL: #1+4i-4i-16i^2# Subtract: #1-16i^2# #i^2=-1# So #1-16(-1)# Multiply: #1+16# Add: #17# Answer link Related questions What is the complex number plane? Which vectors define the complex number plane? What is the modulus of a complex number? How do I graph the complex number #3+4i# in the complex plane? How do I graph the complex number #2-3i# in the complex plane? How do I graph the complex number #-4+2i# in the complex plane? How do I graph the number 3 in the complex number plane? How do I graph the number #4i# in the complex number plane? How do I use graphing in the complex plane to add #2+4i# and #5+3i#? How do I use graphing in the complex plane to subtract #3+4i# from #-2+2i#? See all questions in Complex Number Plane Impact of this question 2275 views around the world You can reuse this answer Creative Commons License