The length of a rectangular garden is three feet less than twice it's width. If the perimeter of the garden is 42 feet, what is the length?

The length is equal to 13. The width is equal to 8.

l = 2w - 3

2l + 2w = 42

Because we have a value for l, we can plug it into the second equation to solve for w.

2 (2w - 3) + 2w = 42

Distributive property.

4w - 6 + 2w = 42

Combine like terms.

6w - 6 = 42

Add 6 to both sides.

6w = 48

Divide both sides by 6.

w = 8

Now that we have a value for w, we can solve for the exact value of l.

l = 2 (8) - 3

l = 16 - 3

l = 13