I think the answer would be D.
There is 30 students from each grade so we have 30/120 already then add 12 from 9th grade math and add 10 more from 10th grade math, then add 7 from 12th grade math.
30 + 12 + 10 + 7 = 59
59/120 students.
Y= 2x because it’s 8/4 which can be divided by 4 and it equals 2x
It looks like the sequence might be
which we can simplify by dividing through by to get
As , both terms, and hence the given sequence will converge to 0.