# How do you solve the equation 63 + [3d - 12] = 21?

##### 1 Answer
Feb 15, 2016

To solve means to isolate d.

#### Explanation:

$63 + 3 d - 12 = 21$

$3 d = 21 + 12 - 63$

$3 d = - 30$

$d = - 10$