Respuesta :

Answer:

D.9a+19b

Step-by-step explanation:

7(a+3b)+2(a-b)

7*a=7a

7*3b=21b

2*a=2a

2*-b=-2b

7a+21b+2a-2b

7a+2a=9a

21b-2b=19b

Hope this helps:)

The answer would be d 9a+19b