the length of a swimming pool is 8m longer than its width and the area is 105m square. justify the answer by representing each situation by a mathematical sentence.

Sagot :

We let the width be x, this would make the length x+8 so:
Area = length * width
105 = (x+8)x
105 = x²+8x
0 = x²+8x-105

We look for two numbers with a product of 105 and an absolute difference of 8.
105 - 1 = 104  X
35 - 3 = 32  X
21 - 5 = 16  X
15 - 7 = 8  √

Therefore:
0 = (x+15)(x-7)
So the possible value of x are -15 and 7. We cannot have a negative value since a length is never negative.

So the width is 7m and the length is 15m.