Question

The width of a rectangle measures (k+ 3) centimeters, and its length

measures (k − 9) centimeters. Which expression represents the
perimeter, in centimeters, of the rectangle

Answer 1

4K-12
P = 2L + 2W
2(K+3) + 2(K-9) = 2K+6+2K-18 = 4K-12

Answer 2

P = 4k-12 centimeters

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

Substitute the given values for l and w, those being (k-9) and (k+3) respectively.

P=2((k-9)+(k+3))
and depending on how the options are written, this is simplified to:
P= 2(2k-12)
and further

P = 4k-12.