Posted by **PreCal** on Sunday, April 3, 2011 at 1:59pm.

Write each expression in problems 1 to 3 in the form a + bi.

1. (8-3i)+(-6+2i)

2. 4/(2-i)

3. (3-2i)^3

I do not understand at all where to start. I tired looking on google to find a way to solve but I didn't get any real help. So please help me!

- PreCal -
**Henry**, Monday, April 4, 2011 at 10:47pm
1. 8 - 6 -3i + 2i = 2 - i.

2. 4 / (2 - i),

Multiply numerator and denominator by 2 + i:

(8 + 4i) / (2 - i)(2 + i),

(8 + 4i) / (4 + 1) = (8 + 4i) / 5.

3. (3 - 2i)^3 = (3 - 2i)^2 (3 - 2i)=

(9 - 12i + 4) (3 - 2i),

(13 - 12i) (3 - 2i),

39 - 26i - 36i - 24 = 15 - 62i.

- PreCal -
**PreCal**, Tuesday, April 5, 2011 at 1:55pm
Alright thank you. Can I also put them in my calculator? I wasn't sure but I did for the first one and got the same answer.

- PreCal -
**Henry**, Tuesday, April 5, 2011 at 4:43pm
That's fine if you don't have to show

your work.

- PreCal -
**PreCal**, Tuesday, April 5, 2011 at 5:27pm
Thank you so much for your help!

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