Add the brackets to make the sum correct for the following equation: 12-11+2-1= 0

By putting the bracket around (11+2-1) you are able to calculate that this then equals 12. This can the be put into the equation 12-(11+2-1)=0 which is 12-(12)=0. This then means that 12-12=0 giving you the correct answer. Therefore, 12-(11+2-1)=0 is the correct answer.