Step-by-step explanation:

Answer:
2. There are 5 students 14 years old 7 grade
Hey there
9a+3+2a+10
You have to collect like terms
To simplify you have to add 9a and 2a. Then 3 and 10
9a+2a= 11a
10+3= 13
The answer is 11a+13
hope this helps <span />
=(-17) - 4
=(-17) + (-4)
=(-21)