|1.4+2又2/5|-5又1/3-|3又1/3-5|若a,b互为相反数,求a+2a+.+50a+b+2b+.+50b的值.-1/2-1/6-1/12-1/20-1/30-1/42-4+(-24)×1/6-(-7)×(-3)(1+1/2)×(1-1/2)×(1+1/3)×(1-1/3)×...×(1+1/99)×(1-1/99)
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![|1.4+2又2/5|-5又1/3-|3又1/3-5|若a,b互为相反数,求a+2a+.+50a+b+2b+.+50b的值.-1/2-1/6-1/12-1/20-1/30-1/42-4+(-24)×1/6-(-7)×(-3)(1+1/2)×(1-1/2)×(1+1/3)×(1-1/3)×...×(1+1/99)×(1-1/99)](/uploads/image/z/3889330-34-0.jpg?t=%EF%BD%9C1.4%2B2%E5%8F%882%2F5%EF%BD%9C-5%E5%8F%881%2F3-%EF%BD%9C3%E5%8F%881%2F3-5%EF%BD%9C%E8%8B%A5a%2Cb%E4%BA%92%E4%B8%BA%E7%9B%B8%E5%8F%8D%E6%95%B0%2C%E6%B1%82a%2B2a%2B.%2B50a%2Bb%2B2b%2B.%2B50b%E7%9A%84%E5%80%BC.-1%2F2-1%2F6-1%2F12-1%2F20-1%2F30-1%2F42-4%2B%EF%BC%88-24%EF%BC%89%C3%971%2F6-%EF%BC%88-7%EF%BC%89%C3%97%EF%BC%88-3%EF%BC%89%EF%BC%881%2B1%2F2%29%C3%97%EF%BC%881-1%2F2%29%C3%97%281%2B1%2F3%29%C3%97%EF%BC%881-1%2F3%29%C3%97...%C3%97%EF%BC%881%2B1%2F99%EF%BC%89%C3%97%EF%BC%881-1%2F99%EF%BC%89)
|1.4+2又2/5|-5又1/3-|3又1/3-5|若a,b互为相反数,求a+2a+.+50a+b+2b+.+50b的值.-1/2-1/6-1/12-1/20-1/30-1/42-4+(-24)×1/6-(-7)×(-3)(1+1/2)×(1-1/2)×(1+1/3)×(1-1/3)×...×(1+1/99)×(1-1/99)
|1.4+2又2/5|-5又1/3-|3又1/3-5|
若a,b互为相反数,求a+2a+.+50a+b+2b+.+50b的值.
-1/2-1/6-1/12-1/20-1/30-1/42
-4+(-24)×1/6-(-7)×(-3)
(1+1/2)×(1-1/2)×(1+1/3)×(1-1/3)×...×(1+1/99)×(1-1/99)
|1.4+2又2/5|-5又1/3-|3又1/3-5|若a,b互为相反数,求a+2a+.+50a+b+2b+.+50b的值.-1/2-1/6-1/12-1/20-1/30-1/42-4+(-24)×1/6-(-7)×(-3)(1+1/2)×(1-1/2)×(1+1/3)×(1-1/3)×...×(1+1/99)×(1-1/99)
|1.4+2.4|-16/5-|10/3-5|=3.8-16/3-5/3=3.8-7=19/5-7=-16/5
a=-b,所以a+b=0,a+2a+……50a+b+2b+……+50b=(a+b)+2(a+b)+……+50(a+b)=0
-1/2-1/6-1/12-1/20-1/30-1/42=-4/6-1/12-1/20-1/30-1/42=-3/4-1/20-1/30-1/42=-4/5-1/30-1/42=-5/6-1/42=-6/7
-4+(-24)×1/6-(-7)×(-3)=-4-4-21=-29
(1+1/2)×(1-1/2)×(1+1/3)×(1-1/3)×...×(1+1/99)×(1-1/99)=3/2×1/2×4/3×2/3×……×100/99×98/99=1/2×100/99=50/99 这个题有规律的,每两项分母相同,前者比分母大一,后者比分母小一,不同分母的两个数可以约分,前面只剩下1/2,后面只剩下100/99,中间部分都能约掉,你可以多写几项来验证