原式=(275+326*274)/[(274+1)*326-51]
=(275+326*274)/(274*326+326-51)
=(276+326*274)/(276+326*274)
=1
(275+326*274)/(275*326-51)
=(275+51+326*274-51)/(275*326-51)
=(326+326*274-51)/(275*326-51)
=(326*275-51)/(275*326-51)
=1
(275+ 326*274)/[(274+1)*326-51]
=(275+326*274)/(274*326+326-51)
=(276+326*274)/(276+326*274)
=1