A rectangular swimming pool is 15 feet long and x feet wide. What is the perimeter when x=12 feet

54 square feet

Step-by-step explanation:

To find perimeter of a rectangle we must use the formula l+l+w+w=p where l and w represent width and length

Since we know length and width is x=12 just substitute so

15+15+12+12=54 so 54 is the perimeter

b

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.