To simplify you use order of operations or PEMDAS
P- Parenthesis
E- Exponents
M- Multiplication
A- addition
S- Subtraction
8-6(3)+13
There's parenthesis so the first thing we have to do is multiply 6 by three which is 18 so then our expression is
8-18+13
since it's just subtraction and addition you can go in any order
8-31
-23
-23 is your answer
