Answer:
1. 21+5f = 61
2. 18+5n=50.50
3. 40+30s=220
Explanation:
1. SUM of 21 and 5 TIMES a number f is 61
From that sentence, sum means addition and times is multiplication, so:
21+5f = 61
2. Let's identify the given:
Monthly fee: 18
Cost of each call: 5
Variable that symbolizes the call: n
Total cost this month: 50.50
Thus, 18+5n=50.50
3. Identify the given:
Charge of tutor: 40
Charge of tutor every student: 30
Variable representing the number of students: s
Total charge: 220
Thus, 40+30s=220