An expanding rectangle has a fixed width of 7 inches and an initial length of 0 inches. the length of the rectangle begins increasing at 2.7 inches per second. write a formula that expresses the perimeter of the rectangle, p (in inches), in terms of the length of the rectangle, l (in inches).

P = (5.4 inches/sec) t + 14 inches for t > 0

Step-by-step explanation:

A formula for the length of this rectangle is L = (2.7 inches/sec) t, where t is the number of seconds.

The standard formula for the perimeter of a rectangle is P = 2L + 2W.

Substituting  (2.7 inches/sec) t for L, we get:

P = 2( (2.7 inches/sec) t ) + 2(7 inches) for t > 0.

This may be simplified slightly:  

P = (5.4 inches/sec) t + 14 inches for t > 0

20

step-by-step explanation: