### Home > A2C > Chapter 9 > Lesson 9.2.1 > Problem9-72

9-72.

Write each of the following expressions in the form $a + bi$.

1. $- 18 - \sqrt { - 25 }$

• $-18-\sqrt{(-1)(25)}$

• $− 18 − 5i$

1. $\frac { 2 \pm \sqrt { - 16 } } { 2 }$

$1 ± 2i$

1. $5 + \sqrt { - 6 }$

$5 + i\sqrt{6}$