Question

A certain high school class consists of juniors and seniors. There are

23 students in the class, and the number of seniors is 7 less than twice the
number of juniors. How many seniors are in the class?

Answer 1

10 SENIORS

Explanation:

x=# of seniors

y=# of juniors

x+y=23, x=2y-7

1. plug the value of x in the second equation into the first
2. (2y-7)+y=23
3. Remove parentheses
4. 2y-7+y=23
5. Combine like terms
6. 3y-7=23
7. Add 7 to BOTH sides
8. 3y=30
9. divide BOTH sides by 3
10. 3y/3=30/3
11. y=10
12. There are 10 juniors in the class

1. FINAL STEPS
2. Plug y (which is 10) into the first equation
3. x+y=23
4. x+10=23
5. subtract 10 from BOTH sides
6. x=13
7. Since X equals the number of seniors, there are 10 seniors in the class