SOLUTION: given the following two complex numbers, a=3+7i and b=-2-2i,calculate the following a+b a-b a*b a/b

Question 100060: given the following two complex numbers, a=3+7i and b=-2-2i,calculate the following
a+b
a-b
a*b
a/b
Found 2 solutions by edjones, timmy1729:
Answer by edjones(8007) (Show Source): You can put this solution on YOUR website!
a=3+7i b=-2-2i
.
a+b
3+7i+(-2-2i)
3+7i-2-2i
group like terms: (3-2)+(7i-2i)
1+5i Ans.
.
a-b
3+7i-(-2-2i)
3+7i+2+2i
(3+2)+(7i+2i)
5+9i Ans
.
a*b
(3+7i)*(-2-2i)
-6-20i-14i^2
-6-20i+14
8-20i Ans
.
a/b
Here it gets a little tricky.
(3+7i)/(-2-2i)
multiply the top and bottom by complex congugate of the denominator:

Ans.
Ed

Answer by timmy1729(23) (Show Source): You can put this solution on YOUR website!
given the following two complex numbers, a=3+7i and b=-2-2i,calculate the following
a+b
a-b
a*b
a/b
Ok, for the most part, treat i like a variable.

a*b is just simply:
Remember that i^2 = -1. So we simplify into:
a/b is
To simplify, you multiply the numerator and denominator by the denominator's complex conjugate which is -2+2i.

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