Answer:
where x denotes number of junior tickets.
Explanation:
Let x denotes number of junior tickets.
Sara sold 10 less senior tickets than junior tickets.
Number of senior tickets

Sara sold 3 times as many sophomore tickets as junior tickets.
Number of sophomore tickets

Senior tickets cost $3, junior tickets cost $5 and sophomore tickets cost $7.
Total amount raised by Sara

Sara raised $782.
So,
