Question

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

Answer 1

Answer:

$1-7i$

Step-by-step explanation:

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

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

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

$=-3+4$

$=1$

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

$=-4-3$

$=-7$

$=1-7i$