Answer: Yes, the equations are correct.
x represents the time that one individual act takes.
y represents the time that one group act takes.
Step-by-step explanation:
the first statement says:
"The first show will last 2 hours, and 12 individual acts, and 6 group acts"
He writes this as:
12*x + 6*y = 120.
then x represents the time that individual acts take.
6 represents the time that group acts take.
120 represents the time in minutes (120 min = 2 hours).
The second statement says:
"The final show will last 30 minutes, and it will include the top 4 individual groups, and the top group act."
this is written as:
4*x + 1*y = 30
And it is consistent with the thing we saw above.
At the right, we have time in minutes, 30 minutes.
x represents the time that each individual act needs, and in this case, we have 4 individual acts.
and y represents the time that the group acts need, and we have only one group act in this case.
Then yes, you must agree with your classmate.