I'm working on this section in my Algebra book called Elimination by Addition Method/Systems using two linear equations and I'm stuck on this word problem.

Can somebody please help me and explain how to set it up and solve it?

Thanks.

Suppose that we have a rectangular book cover. If the width is increased by 2 centimeters, and the length is decreased by 1 centimeter, then the area is increased by 28 square centimeters. However, if the width is decreased by 1 centimeter and the length is increased by 2 centimeters, then the area is increased by 10 square centimeters. Find the dimensions of the book cover.

This is what I tried doing

(W+2)(L-1)= 28

(W-1)(L+2)=10

I know I'm doing something wrong and I cant figure out another way to set up the equations.