Answer:
The other equation is

The length and width are 13 and 8
Explanation:
Given


Required
What is the other equation for the length and width?
x and y represents the length and width respectively.
The perimeter of a rectangle is calculated using:

In this case, it is:

Substitute 42 for perimeter

Divide through by 2


Required: The values of length and width
We have that:


Substitute x - 5 for y in the second equation


Add 5 to both sides


Divide through by 2

Substitute 13 for x in



Hence, the length and width are 13 and 8 respectively