7/19*22/31+9/19*7/31简算

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7/19*22/31+9/19*7/31简算7/19*22/31+9/19*7/31简算7/19*22/31+9/19*7/31简算=7*22/(19*31)+9*7/(19*31)=(7*22+9*

7/19*22/31+9/19*7/31简算
7/19*22/31+9/19*7/31简算

7/19*22/31+9/19*7/31简算
=7*22/(19*31) + 9*7 /(19*31)
=(7*22+9*7)/(19*31)
=7*(22+9)/(19*31)
=7*31/(19*31)
=7/19

把 十九分之七提出来即可

在乘法里b/a×d/c=d/a×b/c,就是说7/19*22/31+9/19*7/31等于7/19*22/31+7/19*9/31.会了吗?

原式=22/19×7/31+9/19+7/31=7/31×(22/19+9/19)=7/19

=22/19x7/31+9/19x7/31
=(22/19+9/19)x7/31
=31/19x7/31
=7/19