Answer: Parking lot is 60m wide
Explanation:
Since the parking lot is x meters, the length of the field would simply be (300-2x)m while the width of the field would be (200-x). The width would also have been 200-2x but we must remember that the field is only covered on 3 sides.
Area of the field is 30,000. This means if we multiply both, we get 30,000.
Mathematically;
(300-2x)(200-x) = 30,000
60,000-300x-400x+ 2x^2 = 30,000
2x^2-700x-30,000= 0
We can see we now have a quadratic equation we need to solve.
2x^2+500x-1200x-30,000= 0
2x(x+250) -120(x+250) = 0
(2x-120)(x+250) = 0
2x-120= 0 or x+250=0
2x = 120or x = -250
x = 120/2 or x= -250
x = 60 or x=-250
We discard x = -100 as x is length and cannot be negative
Hence, x = 60m