157k views
9 votes
Express (4+7i)(2-i) in the form a+ib​

User Jeph
by
5.1k points

1 Answer

5 votes

(4+7i)(2-i)

multiply it out

8-4i +14i -7i squared

i squared is the same as -1

8-4i+14i-7(-1)

8+7-4i+14i

15+10i

divide by common factor which is 5 in this case

3+2i

User Penguinrob
by
4.9k points