结合律表明,当你加或乘任意三个时实数,分组(或关联)的数字不影响结果。
( 一个 + b ) + c = 一个 + ( b + c )
示例1:
( 2 + 3. ) + 5 = 5 + 5 = 10 2 + ( 3. + 5 ) = 2 + 8 = 10
( 一个 b ) c = 一个 ( b c )
示例2:
( 5 ⋅ 7 ) ⋅ 6 = 35 ⋅ 6 = 210 5 ⋅ ( 7 ⋅ 6 ) = 5 ⋅ 42 = 210