423134x846267-423133
423133x846267+423134
=846267-423133
1+423134
= 423134
423135
xét tử số 423134 x 846267 - 423133
= (423134 + 1) x 846267 - 423133
= 423133 x 846267 + 846267 - 423133
= 423133 x 846267 + 423134
ta có : 423134 x 846267 - 423133 / 423133 x 846267 + 423134 =1