Respuesta :
a+a+a = 3a
b+b+b = 3b
So we have 3a+3b which can be written as 3(a+b), answer C.
b+b+b = 3b
So we have 3a+3b which can be written as 3(a+b), answer C.
Well, since a+a=2a, a+a+a=3a, and b+b+b=3b. Therefor, the correct answer is 3a+3b, which can also be factored into 3(a+b), which is answer choice C.
Hope this helps!
-Raiden
Hope this helps!
-Raiden