Answer:
b.
Step-by-step explanation:
The expression b is a function because the x values are all different.
In fact it is a one-to-one function as there is a different value of y for each value of x.
Answer:
A:

B:
With absolute value equations, you can make two equations.

Answer: Use all numbers to add.
2918+49=2967
Estimated.... 2918+49 ≈ 3050
Hope this helps you out.