Well If you are working with PEMDAS(parentesis,exponets,mutiply,divide,addition,subtraction or please excuse my dear aunt sally) You start with parentesis first then work on whatever is next for example: (-4x5)+8 then the answer is 2 because -4x5 is -20 because of the negative sign in front of -4 and then -20+8 you cant so you have to subtract which leaves you with 2 (just because -4x5 is in front doesnt mean that u can always start there if it is like 8+(-4x5) then you work on it backwards! p.s hoped this helped!