# How do you solve d-4 <= (13-d)/3 ?

Sep 13, 2016

$d \le \frac{25}{4}$

#### Explanation:

If I read it correctly - upside down - this is an inequality:

$d - 4 \le \frac{13 - d}{3}$

First multiply both sides by $3$ to get:

$3 d - 12 \le 13 - d$

Add $d + 12$ to both sides to get:

$4 d \le 25$

Divide both sides by $4$ to get:

$d \le \frac{25}{4}$

Any $d$ satisfying the original inequality will satisfy this final one and since all of these operations are reversible, any $d$ satisfying this final inequality will satisfy the original one.