This question you are asking is order of operations also know as PEMDAS: please excuse my dear aunt sally is a great way to remember it.
P: parenthesis
E: exponents
M: multiply (From left to right)
> These 2 can be switched. As long as you are going left to right, you do which one comes first.
D: divide (From left to right)
A: add (From left to right)
> These 2 can be switched. As long as you are going left to right, you do which one comes first.
S: subtract (From left to right)
The answer is: 11
Explanation:
If x is 6, then we can start filling things in. Instead of 2(x+1)-3 we can put 2(6+1)-3. Then we do the parenthesis first because of pemdas. we get 6+1= 7. Then we lay it out. 2 (7) -3. 2 times 7 = 14. Last we subtract 3. 14-3= 11. :) That i how we get the answer. Hope this helps :)