The perimeter, P, of a rectangle is the sum of twice the length and twice the width.P = 2(l+w) unitsP = 2(5)+2(9) unitsP = 4x unitsP = (l+l)+(w+w) unitsP = 2(x+3) units

The answer is P = 2(l+w) units.

This is because when you let the perimeter of the rectangle be P, the length of the rectangle be l and the width of the rectangle be w.

The information above can be expressed as the following equation,
P = 2l + 2w

You can then factorise out the common factor, 2.
P = 2(l+w)

Thus, the answer is P = 2(l+w) units.