When the plus sign comes before the brackets, the brackets are removed and the formula in the brackets remains the same.

When the minus sign comes before the parentheses, remove the parentheses, and the plus sign in the parentheses becomes a minus sign, and the minus sign becomes a plus sign.

1-(4-2*3)

= 1-4+2*3

3+2-(5+3)

=3+2-5-3

5-(3-2+ 1)=5-3+2- 1