用简便方法计算 78×3.6+78×7.4-7.8= 14.25-3.83-0.17

来源:学生作业学帮网 编辑:学帮网 时间:2024/07/05 08:51:33

用简便方法计算 78×3.6+78×7.4-7.8= 14.25-3.83-0.17

7.8x10x3.6+7.8x10x7.4-7.8
=7.8x(36+74-1)
=7.8x(100+10+1)
=7800+78+7.8
=7878+7.8
=7885.8
14.25-3.83-0.17
=14.25-(3.83+0.17)
=14.25-4
=10.25