Answer:
y=310
x=415
Explanation:
x= Holmes Junior High
y= Harper Junior High
x has 105 more students than y. so, x=y+105
and if x and y are merged, you'll have 725 students. so, x+y=725
now you have:
x=y+105
x+y=725
now you can put the x of the first equation, in the second equation to find y :
(y+105)+y=725
2y+105=725
2y=725-105
2y=620
y=310
now put y in either 1st or the second equation. I'm using the 1st equation:
x=310+105
x=415
if anything is unclear, ask freely.