Question

Perform the indicated operation and write the answer in the form a + bi.
(1 + i)(-3 - 4i)

Answer 1

`1-7i`

Explanation:

`\left(1+i\right)\left(-3-4i\right)`

`=\left(1\cdot \left(-3\right)-1\cdot \left(-4\right)\right)+\left(1\cdot \left(-4\right)+1\cdot \left(-3\right)\right)i`

`1\cdot \left(-3\right)-1\cdot \left(-4\right)`

`=-3+4`

`=1`

`1\cdot \left(-4\right)+1\cdot \left(-3\right)`

`=-4-3`

`=-7`

`=1-7i`