几道关于有理数的初中计算题注:“/”就是分数线(1) (-(-1/42)÷(1/6-2/7+2/3-3/14))(2) (1/13-1/2-1/3)÷(-1/78)(3) 1/5×9+1/9×13+……+1/101×105(4)(1/2004-1)×(1/2003-1)×……×(1/10
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![几道关于有理数的初中计算题注:“/”就是分数线(1) (-(-1/42)÷(1/6-2/7+2/3-3/14))(2) (1/13-1/2-1/3)÷(-1/78)(3) 1/5×9+1/9×13+……+1/101×105(4)(1/2004-1)×(1/2003-1)×……×(1/10](/uploads/image/z/5309697-57-7.jpg?t=%E5%87%A0%E9%81%93%E5%85%B3%E4%BA%8E%E6%9C%89%E7%90%86%E6%95%B0%E7%9A%84%E5%88%9D%E4%B8%AD%E8%AE%A1%E7%AE%97%E9%A2%98%E6%B3%A8%EF%BC%9A%E2%80%9C%2F%E2%80%9D%E5%B0%B1%E6%98%AF%E5%88%86%E6%95%B0%E7%BA%BF%EF%BC%881%EF%BC%89+%EF%BC%88-%EF%BC%88-1%2F42%EF%BC%89%C3%B7%EF%BC%881%2F6-2%2F7%2B2%2F3-3%2F14%EF%BC%89%EF%BC%89%EF%BC%882%EF%BC%89+%EF%BC%881%2F13-1%2F2-1%2F3%EF%BC%89%C3%B7%EF%BC%88-1%2F78%EF%BC%89%EF%BC%883%EF%BC%89+1%2F5%C3%979%2B1%2F9%C3%9713%2B%E2%80%A6%E2%80%A6%2B1%2F101%C3%97105%EF%BC%884%EF%BC%89%EF%BC%881%2F2004-1%EF%BC%89%C3%97%EF%BC%881%2F2003-1%EF%BC%89%C3%97%E2%80%A6%E2%80%A6%C3%97%EF%BC%881%2F10)
几道关于有理数的初中计算题注:“/”就是分数线(1) (-(-1/42)÷(1/6-2/7+2/3-3/14))(2) (1/13-1/2-1/3)÷(-1/78)(3) 1/5×9+1/9×13+……+1/101×105(4)(1/2004-1)×(1/2003-1)×……×(1/10
几道关于有理数的初中计算题
注:“/”就是分数线
(1) (-(-1/42)÷(1/6-2/7+2/3-3/14))
(2) (1/13-1/2-1/3)÷(-1/78)
(3) 1/5×9+1/9×13+……+1/101×105
(4)(1/2004-1)×(1/2003-1)×……×(1/1000-1)
几道关于有理数的初中计算题注:“/”就是分数线(1) (-(-1/42)÷(1/6-2/7+2/3-3/14))(2) (1/13-1/2-1/3)÷(-1/78)(3) 1/5×9+1/9×13+……+1/101×105(4)(1/2004-1)×(1/2003-1)×……×(1/10
(1)
(-(-1/42)÷(1/6-2/7+2/3-3/14))=(-(-1/42)÷(-5/42+19/42))=(-(-1/42)÷(1/3))=1/14
(2)
(1/13-1/2-1/3)÷(-1/78)=(-59/78)÷(-1/78)=59
(3)
1/5×9+1/9×13+1/13×17+……+1/101×105
=1/4 *(4/5×9+4/9×13+4/13×17+……+4/101×105)
=1/4*(1/5 -1/9 +1/9 -1/13 +1/13……-1/101 +1/101 -1/105)
=1/4*(1/5 -1/105)
=1/4*(20/105)
=1/21
(4)
1/2004-1)×(1/2003-1)×……×(1/1000-1)
=(-1)^1005*(2003/2004)*(2002/2003)*(2001/2002)……(1000/1001)*(999/1000)
=-999/2004