The perimeter of a rectangle with width y and length x is 40. Write the width, y,
in terms of its length, X.

y = 20 - x

Step-by-step explanation:

Perimeter of a rectangle = 40 units

2 * ( length + width) = 40

  2* (x + y) = 40    {Divide both sides by 2}}

     x + y = 40/2

     x + y = 20       {Subtract x from both sides}

            y = 20 - x

9 sandwiches per hour

step-by-step explanation:

when we have a rate, we want a 1 in the denominator

27/3 = 9

27 sandwiches/ 3 hours = 9 sandwiches/hour