How do you find #abs( -7 + 5i )#? Precalculus Complex Numbers in Trigonometric Form Complex Number Plane 1 Answer Douglas K. Oct 1, 2016 The magnitude of any complex number of the form #a + bi# is #sqrt(a² + b²)# In this case #|-7 + 5i| = sqrt74# Explanation: #|-7 + 5i| = sqrt(-7² + 5²) = sqrt(49 + 25) = sqrt74# 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 1318 views around the world You can reuse this answer Creative Commons License