Solve for each of the formulas for the indicated variable:

If the perimeter of a rectangle is 60ft and its length is 18ft, find its width. (see formula in number 1)

The formula for the perimeter of a rectangle is P = 2l + 2w, where P is the perimeter, l is the length, and w is the width.

Given that the perimeter of the rectangle is 60ft and its length is 18ft, we can substitute these values into the formula and solve for the width:

60 = 2(18) + 2w
60 = 36 + 2w

Subtract 36 from both sides:

60 - 36 = 2w
24 = 2w

Divide both sides by 2:

24/2 = w
12 = w

Therefore, the width of the rectangle is 12ft.

The formula for the perimeter of a rectangle is given by:

Perimeter = 2 * (Length + Width)

We are given that the perimeter is 60ft and the length is 18ft. Let's substitute these values into the formula and solve for the width.

60 = 2 * (18 + Width)

Divide both sides of the equation by 2:

30 = 18 + Width

Next, subtract 18 from both sides of the equation:

30 - 18 = Width

Simplifying:

12 = Width

Therefore, the width of the rectangle is 12ft.