Answer:
The width of the desk is 12 inches.
Explanation:
Given:
The perimeter of the top of a desk is 54 inches.
The length of the desk is 15 inches.
Now, to find the width of the desk.
Let the width of the desk be
.
Putting the formula of perimeter to get the width:
![Perimeter = 2(length + width)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qgl2iuwb9b32irces8jwwe9x3cjslv6sua.png)
⇒
![54=2(15+x)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/k4nn6c1zx5zet4jej6vhrt3uf3dva5gmen.png)
⇒
![54=30+2x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ethv6iubutkz9g5j6klpfc5p5sepsp6m6j.png)
Subtracting both sides by 30 we get:
⇒
![24=2x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/yick6kn61kgf9xuhv1x3fbv6tn8t1a8uhw.png)
Dividing both sides by 2 we get:
⇒
![12=x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/mqfl0s9by5tq4dt8qlgh2snergn7smvwsi.png)
⇒
![x=12\ inches](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2gg0f0g3w4l7u2yi0gpei7s86ubz6idp7d.png)
Therefore, the width of the desk is 12 inches.