Answer:
a
Step-by-step explanation:
[tex]\frac{3x}{x-1}[/tex] + [tex]\frac{8}{x-1}[/tex]
These fractions have a common denominator and so do not require to be altered.
The numerators can be added to simplify, that is
= [tex]\frac{3x+8}{x-1}[/tex]
The remaining fractions have different denominators and would require to be altered before they could be added.