Please please do these please help another human being.

Answer:
2. 1
Step-by-step explanation:
f(0) = 2(0) + 1
To solve these types of equations you just put the number where the variables are.
Answer:
3. 5, 4. 12
Step-by-step explanation:
3.
g(a)=a^2+1
g(-2)=4+1=5
4.
f(x)=x^2+x
f(3)=9+3=12