A rectangle has a perimeter of 60. Its length is 1/2 (n-6) and its width is 2n+5. What is the value of n?

n must be 3

Step-by-step explanation:

The formula for the perimeter of a rectangle of length L and width W is

P = 2L + 2W. Substituting (1/2) (n - 6) for L and 2n + 5 for W, we get:

P = 60 = n - 6 + 4n + 10, or:

60 = 5n + 4, or:

15 = 5n

Then n must be 3.