The width of a rectangle is 3 units less than the length. The area of the rectangle is 28 units. What is the width, in units, of the rectangle?

Answer 1

Let L be the length then the width is (L-3) and we know area is L(W)
So
Area = (L)(L-3)
and Area is
28 so
28=(L)(L-3)
use the distributive property then move your equation to the right hand side and solve for the roots : )
Hint the factors of the quadratic are 7 and 4, you figure out the signs : )