Answer:
s + j = 32
s = 4 + j
Explanation:
The first equation that must form our system is the one that show the total of students. If both, seniors and juniors, in total are 32, we must have:
s + j = 32
The second equation must show the relation between senior and juniors students. We know that there are four MORE seniors than juniors, or in other words, the total amount of seniors equal to the amount of juniors plus 4 more students:
s = 4 + j
So, your system must be formed by
s + j = 32 (a)
s = 4 + j (b)
If you want the resolution, just replace (a) in (b). You should find s=18 and j=14.