急求3道数学简便运算,9:00之前给过程结果 47*11/35 (1/6+7/8-1/4)除以24 (1/2+1/3+1/4+.1/19+1/20)*(1+1/2+1/3+1/4.1/19)-(1+1/2+1/3+.1/20)*(1/2+1/3+1/4+.1/19)(/表示分数线)
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![急求3道数学简便运算,9:00之前给过程结果 47*11/35 (1/6+7/8-1/4)除以24 (1/2+1/3+1/4+.1/19+1/20)*(1+1/2+1/3+1/4.1/19)-(1+1/2+1/3+.1/20)*(1/2+1/3+1/4+.1/19)(/表示分数线)](/uploads/image/z/10286003-11-3.jpg?t=%E6%80%A5%E6%B1%823%E9%81%93%E6%95%B0%E5%AD%A6%E7%AE%80%E4%BE%BF%E8%BF%90%E7%AE%97%2C9%3A00%E4%B9%8B%E5%89%8D%E7%BB%99%E8%BF%87%E7%A8%8B%E7%BB%93%E6%9E%9C+++++47%2A11%2F35+++++%EF%BC%881%2F6%2B7%2F8-1%2F4%EF%BC%89%E9%99%A4%E4%BB%A524+++++%281%2F2%2B1%2F3%2B1%2F4%2B.1%2F19%2B1%2F20%29%2A%281%2B1%2F2%2B1%2F3%2B1%2F4.1%2F19%29-%281%2B1%2F2%2B1%2F3%2B.1%2F20%EF%BC%89%2A%EF%BC%881%2F2%2B1%2F3%2B1%2F4%2B.1%2F19%EF%BC%89%28%2F%E8%A1%A8%E7%A4%BA%E5%88%86%E6%95%B0%E7%BA%BF%EF%BC%89)
急求3道数学简便运算,9:00之前给过程结果 47*11/35 (1/6+7/8-1/4)除以24 (1/2+1/3+1/4+.1/19+1/20)*(1+1/2+1/3+1/4.1/19)-(1+1/2+1/3+.1/20)*(1/2+1/3+1/4+.1/19)(/表示分数线)
急求3道数学简便运算,9:00之前给过程结果
47*11/35
(1/6+7/8-1/4)除以24
(1/2+1/3+1/4+.1/19+1/20)*(1+1/2+1/3+1/4.1/19)-(1+1/2+1/3+.1/20)*(1/2+1/3+1/4+.1/19)
(/表示分数线)
急求3道数学简便运算,9:00之前给过程结果 47*11/35 (1/6+7/8-1/4)除以24 (1/2+1/3+1/4+.1/19+1/20)*(1+1/2+1/3+1/4.1/19)-(1+1/2+1/3+.1/20)*(1/2+1/3+1/4+.1/19)(/表示分数线)
第一题:
47*11/35
=35*11/35 + 12*11/35
=11 + 7*11/35 + 5*11/35
=11 + 11/5 + 11/7
=11 + 2 + 1/5 + 1 + 4/7
=14 + 27/35
第二题:
(1/6+7/8-1/4)/24
1*4 + 7*3- 1*6 1
=——————— * —
24 24
=19/576
第三题:
(1/2+1/3+1/4+.1/19+1/20)*(1+1/2+1/3+1/4.1/19)-(1+1/2+1/3+.1/20)*(1/2+1/3+1/4+.1/19)
(1/2+1/3+1/4+.1/19+1/20)=a
(1/2+1/3+1/4+.1/19) =b
原式=a*(b+1) - (a+1)*b
=ab + a - ab - b
=a-b
=1/20
( * 乘 / 除或分数线)
517/35=14.771428571428571428571428571429
19/576=0.03298611111111111111111111111111
0
(1)47*11/35=(35+12)*11/35=11+12*11/35=11+(10+2)*11/35
=11+110/35+22/35=13+22/35
(2)(1/6+7/8-1/4)/24
=(4/24+21/24-6/24)/24
=19/(24*24)
(3)令1/2+1/3+1/4+...1/19=a
原式=(a+1/20)(1+a) -(1+a+1/20)*a
=a+a^2+1/20 +a/20-a-a^2-a/20
=1/20
(1)47*11/35
=(35+12)*11/35
=11+12*11/35
=11+(10+2)*11/35
=11+110/35+22/35
=13+22/35
(2)(1/6+7/8-1/4)/24
=(4/24+21/24-6/24)/24
=19/(24*24)
(3)设1/2+1/3+1/4+...1/19=x<...
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(1)47*11/35
=(35+12)*11/35
=11+12*11/35
=11+(10+2)*11/35
=11+110/35+22/35
=13+22/35
(2)(1/6+7/8-1/4)/24
=(4/24+21/24-6/24)/24
=19/(24*24)
(3)设1/2+1/3+1/4+...1/19=x
原式=(x+1/20)(1+x) -(1+x+1/20)*x
=x+x^2+1/20 +x/20-x-x^2-x/20
=1/20
收起
47*11/35=517/35
(1/6+7/8-1/4)除以24=(1/6+5/8)/24=19/576
(1/2+1/3+1/4+......1/19+1/20)*(1+1/2+1/3+1/4......1/19)-(1+1/2+1/3+......1/20)*(1/2+1/3+1/4+......1/19)=0