Question

A farmer has a rectangular field with dimensions $2m+7$ and $m-2$. If the field has an area of 51 square units, what is the value of $m$?

Answer 1

Area is given by the formula
  Area = length*width
Filling in the given information, we have
  51 = (2m+7)*(m-2)
  2m² +3m -65 = 0
  (m -5)(2m +13) - 0
  m = -13/2 or 5
Since dimensions of physical objects are non-negative, the value of m is 5.

Answer 2

m = 5 because if you create an equation you get 2m^2 + 3m - 65 = 0 then you factor find the two roots and take the positive one and viola your answer is 5