first you have to follow the rule PEMDAS, which would mean doing 3×6, which would get you 18, with that,you do 3-18 and you would get -15, then you would do -15 + 2 and get -13. fyi, PEMDAS is parentheses, exponents, multiplication, division, addition, and subtraction, you also always go from right to left in an equation or expression.