Answer:
Let the number of brownies made by Rachel and Trish be R and T respectively.
R+T= 84 ---------(1)
R= 5(12)= 60
Substitute into (1):
60 + T = 84
T= 84-60
T= 24
Therefore, number of pans of brownies made by Trish
= 24÷12
=2
Alternatively,
Let the number of pans of brownies made by Trish be x.
Total number of pans of brownies= 84/12= 7
Since Rachel contributed 5 pans,
x+5=7
x= 7-5= 2
Thus, Trish made 2 pans of brownies.