几道简单巧算题(过程需完整)999+99.9+9.99+0.999(4.5×7.2×9.1)除以(1.5×1.3×2.4)999.9×999.9+199.993.6×31.4+43.9×6.4(2.5+3.7+1)×(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)请在1小时之内
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![几道简单巧算题(过程需完整)999+99.9+9.99+0.999(4.5×7.2×9.1)除以(1.5×1.3×2.4)999.9×999.9+199.993.6×31.4+43.9×6.4(2.5+3.7+1)×(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)请在1小时之内](/uploads/image/z/2678065-25-5.jpg?t=%E5%87%A0%E9%81%93%E7%AE%80%E5%8D%95%E5%B7%A7%E7%AE%97%E9%A2%98%EF%BC%88%E8%BF%87%E7%A8%8B%E9%9C%80%E5%AE%8C%E6%95%B4%EF%BC%89999%2B99.9%2B9.99%2B0.999%EF%BC%884.5%C3%977.2%C3%979.1%EF%BC%89%E9%99%A4%E4%BB%A5%EF%BC%881.5%C3%971.3%C3%972.4%EF%BC%89999.9%C3%97999.9%2B199.993.6%C3%9731.4%2B43.9%C3%976.4%EF%BC%882.5%2B3.7%2B1%EF%BC%89%C3%97%282.5%2B3.7%2B0.6%29%E2%80%94%EF%BC%881%2B2.5%2B3.7%2B0.6%EF%BC%89%C3%97%EF%BC%882.5%2B3.7%EF%BC%89%E8%AF%B7%E5%9C%A81%E5%B0%8F%E6%97%B6%E4%B9%8B%E5%86%85)
几道简单巧算题(过程需完整)999+99.9+9.99+0.999(4.5×7.2×9.1)除以(1.5×1.3×2.4)999.9×999.9+199.993.6×31.4+43.9×6.4(2.5+3.7+1)×(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)请在1小时之内
几道简单巧算题(过程需完整)
999+99.9+9.99+0.999
(4.5×7.2×9.1)除以(1.5×1.3×2.4)
999.9×999.9+199.99
3.6×31.4+43.9×6.4
(2.5+3.7+1)×(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)
请在1小时之内
几道简单巧算题(过程需完整)999+99.9+9.99+0.999(4.5×7.2×9.1)除以(1.5×1.3×2.4)999.9×999.9+199.993.6×31.4+43.9×6.4(2.5+3.7+1)×(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)请在1小时之内
999+99.9+9.99+0.999
=1000-1+100-0.1+10-0.01+1-0.001
=1000+100+10+1-(1+0.1+0.01+0.001)
=1111-1.111
=1109.999
(4.5×7.2×9.1)除以(1.5×1.3×2.4)
=3(1.5×1.3×2.4)除以(1.5×1.3×2.4)
=3
3.6×31.4+43.9×6.4
=3.6*31.4+31.4*6.4+12.5*6.4
=31.4(3.6+6.4)+12.5*0.8*8
=31.4*10+10*8
=314+80
=394
(2.5+3.7+1)×(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)
=(2.5+3.7)*(2.5+3.7+0.6)+(2.5+3.7+0.6)-(2.5+3.7+0.6)*(2.5+3.7)-(2.5+3.7)
=(2.5+3.7+0.6)-(2.5+3.7)
=0.6
1. 999+99.9+9.99+0.999
=(1000-1)+(100-0.1)+(10-0.01)+(1-0.001)
=1000+100+10+1-1-0.1-0.01-0.001
=1111-1.111
=1109.889
2. 999.9*999.9+199.99
=(1000-0.1)²+200-0.01
=1000²-200+0.01+200-0.01
=1000000
.
1:999+99.9+9.99+0.999=
1000+100+10+1-1-0.1-0.01-0.001=1110-0.111=1109.889
2:(4.5×7.2×9.1)/(1.5×1.3×2.4)=3*7*3=63 (4.5和1.5;7.2和2.4;9.1和1.3 分别约分)
3:999.9×999.9+199.99=(1000-0.1)*(1000-0.1)+...
全部展开
1:999+99.9+9.99+0.999=
1000+100+10+1-1-0.1-0.01-0.001=1110-0.111=1109.889
2:(4.5×7.2×9.1)/(1.5×1.3×2.4)=3*7*3=63 (4.5和1.5;7.2和2.4;9.1和1.3 分别约分)
3:999.9×999.9+199.99=(1000-0.1)*(1000-0.1)+200-0.01=1000 000-200+0.01+200-0.01=1000 000
4:3.6×31.4+43.9×6.4=3.6×31.4+(31.4+12.5)×6.4=3.6×31.4+31.4×6.4+12.5*6.4
=31.4*(3.6+6.4)+12.5*8*0.8=314+100*0.8=394
5:(2.5+3.7+1)×(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)=
(2.5+3.7)×(2.5+3.7+0.6)+(2.5+3.7+0.6)—(1+2.5+3.7+0.6)×(2.5+3.7)=
(2.5+3.7)×【2.5+3.7+0.6-—(1+2.5+3.7+0.6)】+(2.5+3.7+0.6)=-(2.5+3.7))+(2.5+3.7+0.6)=0.6 一楼的第一题算错了..哈哈
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