You should use Order of Operations or PEDMAS for this (Parenthesis, Exponents, Division and Multiplication in the order they appear, Addition and Subtraction in the order they appear). So we do the 2+12 because that is in parentheses first which gives 14-3+6. Next we do 14-3 because there are no exponents and no division or multiplication, which gives 11+6. This yields your answer, 17.
