Respuesta :

Answer:

[tex]\huge\boxed{\sf f(a) = 2a}[/tex]

Step-by-step explanation:

-3a + 6b = a + 4b

Isolate b

6b - 4b = a + 3a

2b = 4a

b = 4a / 2

b = 2a

Replace b by f(a)

f(a) = 2a

[tex]\rule[225]{225}{2}[/tex]

Hope this helped!

~AH1807