How do you simplify expressions with imaginary numbers?

Such as:
i^15
or
(25+17i)-(-23-18i)

1 Answer
Apr 26, 2018

Explanation

Explanation:

i^2=-1 since i=\sqrt(-1)
i^15=i^(2(7)+1)=(i^2)^7(i)=(-1)^7(i)=-1(i)=-i

Treat the i like a variable in the second case, but don't solve for it since it already has a value.
(25+17i)-(-23-18i)
25+17i+23+18i (simplify signs)
48+35i (add like terms)