Respuesta :

Answer:

[tex]\frac{3a+b}{9}[/tex]

Step-by-step explanation:

Both fractions have a common denominator of 9

Add the numerators, placing them over 9

= [tex]\frac{3(a-b)+4b}{9}[/tex]

= [tex]\frac{3a-3b+4b}{9}[/tex]

= [tex]\frac{3a+b}{9}[/tex]