Find the area of the rectangle, in cm, with width 4x and length (y+5). Then calculate the area for x = 7 and y = 8.

To start, we need to state that the area of a rectangle is the length multiplied by the width. Therefore, the area will be 4x multiplied by (y+5). Now to do this we need to expand the bracket. To expand the bracket we multiply the outside term by each term inside the bracket.First, 4xy = 4xy.Second, 4x5 = 20x.Then we add the two terms, because of the plus sign inside the bracket, giving us a total area, in cm, of 4xy + 20x.We are then asked to calculate this area for x = 7 and y = 8. We do this simply by substituting these value into the area we just worked out.Giving, 478 + 20*7 = 224 + 140 = 364cm²