Respuesta :

Hello,

First, you distribute: 
7x+(−3)(9)+(−3)(7x) and it turns into 7x+−27+21x

Next, you must combine like terms:
 7x+−27+21x = (7x+21x)+(−27) = 14x+27

So, 14x-27 is your total answer.

I hope I helped :)