Joshua, remember the order of operations, PEMDAS.
We start with the parentheses. 3 - 4 = -1
We have no exponents, so we go to multiplication and division. The 2 in front of the parenthesis means to multiply, so 2(-1) = -2
Then we go to addition and subtraction. We now have -2 + 6 = 4
So, your answer is 4. Hope this helps!