8又11/13-(2.75+1又11/13)+5又3/4
=8又11/13-2.75-1又11/13+5又3/4
=8又11/13-1又11/13+5.75-2.75
=7+3
=10
51*2.08+1.7*37.6
=1.7*30*2.08+1.7*37.6
=1.7*(62.4+37.6)
=1.7*100
=170
18*2/11-0.65*7/13+9*18/11+0.65除以13/7
=18*2/11+9*18/11+0.65*7/13-0.65*7/13
=2*18/11+9*18/11+0
=(2+9)*18/11
=11*18/11
=18
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1.=8又11/13-2又3/4-1又11/13+5又3/4 =8又11/13-1又11/13+5又3/4-2又3/4=10
2.=5.1*20.8+1.7*37.6=1.7*3*20,.8+1.7*37.6=1.7*(3*20.8+37.6)=1.7*100=170
3.=18*2/11+9*18/11-0.65*7/13+0.65*7/13
=18