Math question please answer full details

Question

A small plot of land is used for a Garden. It has a length of "x" ft., and a width that is 40ft less than its length. A farmer will only use the land if it's area measures 2100 square feet. What are the dimensional values of the land?

Answer 1

length = x

width = x-40

area = x.(x-40)

area required = 2100

2100 = x(x-40)

2100 = x²-40x

0 = x²-40x-2100

Solving this using the quadratic formula, we get x = 70; x = -30

Since the length cannot be negative, we take the positive value of 70 as our answer. Therefore, the length is 70, and the width is 30 (70-x = 70-40 = 30).