A piece of land is to be fenced and subdivided as shown so that each rectangle has the same dimensions. Express the total amount of fencing needed as an algebraic expression in x.

There are 3 rectangles.

In the plane, each rectangle has 2x + 7 horizontal side.

The fence covers 3 horizontal sides = > 3 (2x + 7)

In the plane, the vertical sideis x. And the fence covers 4 vertical sides = > 4x

Then the total amount of fecncin is: 3 (2x+7) + 4x = 6x + 21 + 4x = 10x + 21

Answer: 10x + 21