SOLUTION: write in standard form,a+bi. 21-3i/1-3i

Algebra ->  Linear-equations -> SOLUTION: write in standard form,a+bi. 21-3i/1-3i      Log On


   

Question 310369: write in standard form,a+bi.

21-3i/1-3i
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
write in standard form,a+bi.
%2821-3i%29%2F%281-3i%29
Multiply by the conjugate of the denominator over itself
%2821-3i%29%2F%281-3i%29 * %281%2B3i%29%2F%281%2B3i%29
FOIL the numerator and denominators (center terms cancel)
%2821%2B63i-3i-9i%5E2%29%2F%281-9i%5E2%29 = %2821%2B60i-9%28-1%29%29%2F%281-9%28-1%29%29 = %2821%2B60i%2B9%29%2F%281%2B9%29 = %2830%2B60i%29%2F%2810%29
Cancel 10 into 30 and 60 resulting in:
3 + 6i