Answer:
A
Step-by-step explanation:
We can solve this problem by eliminating wrong answers
It can be b because there is no 3
It can be c because the equation would be 4+3
And it can be d because the equation would be 3x+4
so it must be a
option A is correct
as additional page costs is not fixed so there will be any value of x with multiply by 4
and the fixed remain only one time so it remains fixed and 3 is also fixed.
