Performing Arithmetic with Complex Numbers

We can simplify the given expression by combining like terms. Let's start with multiplying the expressions.

(7 + 5 i) (8 - 6 i)

Multiply expressions

DistrDistribute

(7 + 5 i)

8 (7 + 5 i) - 6 i (7 + 5 i)

DistrDistribute

8

56 + 40 i - 6 i (7 + 5 i)

DistrDistribute

(- 6 i)

56 + 40 i - 42 i - 30 i^{2}

i^{2} = - 1

56 + 40 i - 42 i - 30 (- 1)

- a (- b) = a \cdot b

56 + 40 i - 42 i + 30

AddSubTermsAdd and subtract terms

86 - 2 i

Performing Arithmetic with Complex Numbers 1.12 - Solution