Question 100060
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:{{{((3+7i)/(-2-2i))*((-2+2i)/(-2+2i))}}}
{{{(-6-8i+14i^2)/(4-4i^2)}}}
{{{(-6-8i-14)/8}}}
{{{(-20-8i)/8}}}
{{{-5/2-i}}} Ans.
Ed