SOLUTION: 1. When 3+4i / 2+i is expressed in the for a+bi, what is the value of a? I don't understand why the answer is 2. 2. (i+1)(3-i)+(2i-1) I tried multiplying the first two se

Algebra ->  College  -> Linear Algebra -> SOLUTION: 1. When 3+4i / 2+i is expressed in the for a+bi, what is the value of a? I don't understand why the answer is 2. 2. (i+1)(3-i)+(2i-1) I tried multiplying the first two se      Log On


   



Question 46996This question is from textbook CLEP Official Study Guide
: 1. When 3+4i / 2+i is expressed in the for a+bi, what is the value of a?
I don't understand why the answer is 2.
2. (i+1)(3-i)+(2i-1)
I tried multiplying the first two sets and adding the like terms with the third set but I'm not coming up with the correct answer.
This question is from textbook CLEP Official Study Guide

Answer by mathchemprofessor(65) About Me  (Show Source):
You can put this solution on YOUR website!
1.Multiplying and dividing with conjugate of 2+i in the given expression, we get
(3+ 4i)(2-i)/(2+i)(2-i)=(6-3i+8i-4i^2)/(4-i^2)=(10+5i)/(4+1)=(10+5i)/5=2+i=a+bi
So, a=2
2.(i+1)(3-i)+(2i-1)=(3i-i^2+3-i)+(2i-1)=(2i+1+3)+(2i-1)=4i+3