First figure all of the dimensions of the rectangle by dividingthe known area by the given side.
10xy divided by 5x is 2y.
To show the area as a product, write the dimensions multiplied together.
(2y + 4)(5x + 3)
Find the areas of all of the sections by multiplying the dimensions together, then add the areas to express as a sum.
6y + 20x + 10xy + 12
Use the same method from part (a) to solve part (b).