Bedmas

Bedmas stands for brackets,exponents,divide,multiplication,addition,subtraction

Bedmas is an acronym to help remember an order of operations in algebra basics. acronym is an aobreviation formed from the inital letters of words and pronounced as a word 

6 - 9 divided by 3 (9 x 6) =
 so what we do first is the brackets cause its the closest one to the top so
(9 x 6) = 54 then we have to do the next one on the list. So now we have to do the divided by cause its the most closest to the top that we can see 6 - 9 divided by 3  = 54. 9 divided by 3 =3 so then its
6 - 3 x 54. so we do 3 x 54 = 162 then 6 - 162 = -156