The parenthesis are just there to show the two different terms.
You would do x - - 2x, the double negative would turn to an addition sign and it would be x + 2x= 3x
You would then do the other numbers and it would be 1 - -5. Once again the negatives will change to addition and it would be 1+5=6.
Your final answer would be 3x + 6 once you put it all together.
Hope this helped!