A farmer wants to increase the area of his rectangular pen but keep the pen a rectangular shape. He decides to add 1.3 meters of fencing to the width of the pen, but the length will remain 10.4 meters. The new area will be 81.12 square meters.
Which equation can be used to determine the original width, w, of the pen?
10.4(w+1.3)=81.12
1.3(w+10.4)=81.12
10.4w + 1.3 = 81.12
1.3w + 10.4 = 81.12
