Answer:
Explanation:
First
a+s=375
a=375-s
Next
5a+3s=1375, now using a found above makes this equation become
5(375-s)+3s=1375
1875-5s+3s=1375
1875-2s=1375
-2s=-500
s=250, since a=375-s
a=375-250
a=125
So 125 adult and 250 student tickets were sold.