Answer:
The friends will each have passed _33_ scales in _7_ weeks.
Explanation:
We must write an equation for the number of scales that Nick approves and an equation for the number of scales that Mary approves.
For Nick we have:
5 initial scales
Nick has committed to approve 4 scales per week. Let's call x the number of weeks.
So the number of scales and for Nick is:

For Mary we have:
12 initial scales
Mary has committed to approve 3 scales per week. Let's call x the number of weeks.
So the number of scales and for Mary is:

To know when the two friends have passed the same number of scales we must equal both equations and solve for x:



And
