Question

The length of a swimming poollane

is 10 more than 2 times the width.
If the area is 300 square meters,
find the width of the lane. Write a
quadratic equation which can be
used to find x, the width of the
pool.

Answer 1

x²+5x - 150 = 0

Explanation:

Let the length be y and width be x

If the length of a swimming pool is 10 more than 2 times the width, then;

y = 2x+10 ...1

Since the Area is 300m²

A = xy

300 = xy .... 2

Substitute 1 into 2

300 = x(2x+10)

300 = 2x²+10x

Rearrange

2x²+10x - 300 = 0

Divide through by 2

x²+5x - 150 = 0

This gives the required quadratic expression