Respuesta :

Answer:

7x+17

Step-by-step explanation:

(3x-5) +(4x+12)

I like to line them up vertically

 (3x-5)

+(4x+12)

----------------

  7x+17

PEMDAS
parenthesis
exponents
multiplication and division (whichever comes first)
addiction and subtraction (whichever comes first)