Whats not affected by the
others outcome
What we need to do is divide 18 by 8 because 18 cups of flour makes 8 loaves of bread. By using a calculator, 18/8 = 2 1/4.
Area of Rectangle = length times width
lets say length = 2x-4
width = x+5
Note: you can switch these around, width could be 2x-4 and length could be x+5, it doesnt matter.
With that being said:
length * width = area
(2x-4)(x+5)=area
FOIL (First Outer Inner Last)

Simplify: