Question

Find the sum or the difference"type your answer in the form a+bi"

Answer 1

5 - 9i

Step-by-step explanation:
`\begin{gathered} \text{Given:} \\ (3\text{ - 4i) - (5 + 4i) - (-7 + i)} \end{gathered}`

To solve the question above, we need to expand the parenthesis:

`\begin{gathered} 3\text{ - 4i - (5) -(4i) -(-7) -(i)} \\ mu\text{ltiplication of same signs give positive sign} \\ m\text{ ultiplication of opposite signs give negative sign} \\ 3\text{ - 4i - 5 - 4i + 7 - i} \end{gathered}`

collect like terms:

`\begin{gathered} 3\text{ - 5 + 7 -4i - 4i - i} \\ =\text{ 5 }-\text{ 9i} \end{gathered}`