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数学计算题,能简算的简算,

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数学计算题,能简算的简算,
1.1+2-3+4+5-6+7+8-9+…+97+98-99
2.200×(1-1/2)×(1-1/3)×(1-1/4)×…×(1-1/100)
3.6.25×8.27×16+3.75×0.827×8
4.28.9×61.3+111×6.15
5.3.1416×25²-3.1416×15²
6.1997×20002000-2000×19971997
7.(0.3(3的循环)×0.1875+1/400)×65
8.(2又1/2003×9又5/8+7又2002/2003×9.625)÷96又1/4
9.2002÷2002又2002/2003+1/2004
10.1/3+3/4+2/5+5/7+7/8+9/20+10/21+11/24+19/35
数学计算题,能简算的简算,
1.1+2-3+4+5-6+7+8-9+…+97+98-99
=0+3+6+9+…+96=32(3+96)/2=16(100-1)=1584
2.200×(1-1/2)×(1-1/3)×(1-1/4)×…×(1-1/100)
=200*1/2*2/3*3/4*…*99/100=200*1/100=2
3.6.25×8.27×16+3.75×0.827×8
=(6.25×20+3.75)×0.827×8=128.75×0.827×8=851.81
4.28.9×61.3+111×6.15
=1771.57+682.65=2454.22
5.3.1416×25²-3.1416×15²
=3.1416*40*10=1256.64
6.1997×20002000-2000×19971997
=1997*2000*10001-2000*1997*10001=0
7.(0.3(3的循环)×0.1875+1/400)×65
=(1/3*0.1875+1/400)*65=(25/400+1/400)*65=169/40=4.225
8.(2又1/2003×9又5/8+7又2002/2003×9.625)÷96又1/4
=(2*2003+1+8*2003-1)/2003*77/8*96.25=96.25^2=9264.0625
9.2002÷2002又2002/2003+1/2004
=2002*2003/(2002*2004)+1/2004=1
10.1/3+3/4+2/5+5/7+7/8+9/20+10/21+11/24+19/35
=(1/3+10/21)+(5/7+19/35)+(3/4+7/8+11/24)+(2/5+9/20)
=17/21+44/35+50/24+17/20
=(85+132)/105+(250+102)/120=217/105+352/120=4200/840=5