Remove The Brackets Four Columns To

Abstract

When performing integer addition and subtraction, first remove the parentheses. Removing parentheses is the basis of integer addition and subtraction. How to remove parentheses correctly? Please pay attention to the following points: 1. Pay attention to the symbols in front of the brackets, and use the rule of removing brackets: if there is a "+" sign before the brackets, the items in the brackets will remain unchanged after the brackets are removed; if there is a "-" before the brackets ”, after removing the brackets, the symbols in the brackets must be changed. To prevent the mistake of changing only the first item in parentheses and forgetting to change the symbols of the rest. Example 1 Remove the brackets: (1) sa+(-6c-3b); (2) 2a-(3b+Zc). Analysis Because the symbol before the brackets in the formula (1) is the "+" sign, the items in the brackets after removing the brackets remain unchanged; (2) The brackets in the formula are preceded by a "-" sign, so after the brackets are removed, there is a "-" sign. All must be changed. Solution (l) original formula one sa-6c-3b; (2) original formula one Za-3b-Zc. 2. Note that the coefficients before the parentheses are not