Answer:
x²+5x - 150 = 0
Step-by-step 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
