Answer:
The expression for the perimeter of the rectangle is: 
Step-by-step explanation:
Perimeter of a rectangle:
A rectangle has length l and width w. It's perimeter is given by:

In this question:

So

The expression for the perimeter of the rectangle is: 
Answer:
141 cookies
Step-by-step explanation:
amount of cookies
= 9(15) + 6
= 135 + 6
= 141
Well I tried doing it but depends what your trying to do with the equation but I got
x= -a/3 - 5d/3
1 and half hour
= 60 minutes+ 30 minutes
= 90 minutes
Now,
Uzanne need 15 minutes to do 10 problems
Uzanne need 1 minute to complete 10/15 problems
Uzanne need 90 minutes to do
= (10/15)*90
=(2/3)*90
=2*30
=60 problems