49x49/50
=49x(1-1/50)
=49-49x1/50
=49-49/50
=48又1/50
方法1、
49×49/50
=(50-1)×49/50
=50×49/50-1×49/50
=49-49/50
=48又1/50
方法2
49×49/50
=49×(1-1/50)
=49×1-49×1/50
=49-49/50
=48又1/50
=49*(1-1/50)=49-49/50=48又1/50=48.02
49×49/50
=(50—1)×49/50
=50×49/50—49/50
=49—49/50
=48+(1—49/50)
=48+(50/50—49/50)
=48+1/50
=48又1/50
49x49/50
=(50-1)(50-1)/50
=(2500-100+1)/50
=50-2+1/50
=48+1/50