12) 12, 8
12 - 8 = 4
12 + 8 = 20
Answer: 4 < x <span>< 20
13) 11, 3
11 - 3 = 8
11 + 3 = 14
Answer: 8 </span>< x <span>< 14
Hope this helps :)</span>
Answer:

Step-by-step explanation:
Take out 8m as a factor from the top side of the equation. You are left with 
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: