先看下面两个例子：例1计算：解（1）原式=（去括号）（合并同类二次根式）。（2）原式（去括号）（合并同类二次根式）由此例可知，当各二次根式都是最简二次根式时，进行二次根式的加减运算只须做两件事：一是去括号，二是合并同类二次根式．例2计算：（化二次根式为最简二次 First look at the following two examples: Example 1 Calculation: Solution (1) Original = (to bracket) (merging the same type of secondary root). (2) The original formula (the parentheses) (merging the same kind of secondary roots) This example shows that when each secondary root is the simplest secondary root, the addition and subtraction of secondary roots only needs to do two things: One is to go brackets, the second is to merge the same type of secondary roots. Example 2 Calculation: (The secondary root formula is the simplest