SOLUTION: Perform the specified operations and write your answer in standard form. (4+ 3i)(-7 + 4i) (eg. 2, D, E) College Algebra ISBN-13: 978-0-618-77629-0

Algebra ->  Inequalities -> SOLUTION: Perform the specified operations and write your answer in standard form. (4+ 3i)(-7 + 4i) (eg. 2, D, E) College Algebra ISBN-13: 978-0-618-77629-0       Log On


   

Question 145562: Perform the specified operations and write your answer in standard form.

(4+ 3i)(-7 + 4i) (eg. 2, D, E)
College Algebra ISBN-13: 978-0-618-77629-0
Thanks
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Perform the indicated operation:
%284%2B3i%29%28-7%2B4i%29 Use the FOIL method to multiply:
%284%2B3i%29%28-7%2B4i%29+=+-28%2Bhighlight%2816i-21i%29%2B12i%5E2 Combine like-terms and substitutei%5E2+=+-1
-28-5i%2B12%28-1%29+=+-40-5i or -%2840%2B5i%29