Question

A small garden measures 8 ft by 7 ft. A uniform border around the garden increases the total area to 110 ft 2. What is the width of the border?

Answer 1

Answer: 3

Explanation:

You can answer this question by using the equation

(8+x)(7+x)=110

The x represents the width, as we do not know the area. If you simplify the equation, it becomes 56+15x+x2=110.

If you move all the terms to the left side, and rearrange it, it can become x^2+15x-54=0

This can be simplified into (x-3)(x+18)=0

This equation makes it so that x is either 3 or -18. It is not possible for a width to be -18, so the width must be 3.