Answer:
The equation in standard form is:
x^2-40x-6000 = 0
Explanation:
Let the length of the field be x yards.
Now the width of the field is 40 yards less than the length of the field.
Thus, the width of the field would be (x-40) yards
Now, to calculate the area of the field, we simply multiply the length of the field by the width of the field.
Hence;
Since the shape is rectangular, the area is the product of the length and that of the width
x(x-40) =6,000
x^2 -40x = 6,000
x^2-40x-6000 = 0