丨x+2丨+丨y-3丨=0 则x+y的值为 绝对值最小的有理数是?1×2\1+2×3\1+3×4\1+.+n(n+1)=2×4\1+4×6\1+6×8\1+.+2006×2008\1等于?
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![丨x+2丨+丨y-3丨=0 则x+y的值为 绝对值最小的有理数是?1×2\1+2×3\1+3×4\1+.+n(n+1)=2×4\1+4×6\1+6×8\1+.+2006×2008\1等于?](/uploads/image/z/4324623-15-3.jpg?t=%E4%B8%A8x%2B2%E4%B8%A8%2B%E4%B8%A8y-3%E4%B8%A8%3D0+%E5%88%99x%2By%E7%9A%84%E5%80%BC%E4%B8%BA+%E7%BB%9D%E5%AF%B9%E5%80%BC%E6%9C%80%E5%B0%8F%E7%9A%84%E6%9C%89%E7%90%86%E6%95%B0%E6%98%AF%3F1%C3%972%5C1%2B2%C3%973%5C1%2B3%C3%974%5C1%2B.%2Bn%EF%BC%88n%2B1%29%3D2%C3%974%5C1%2B4%C3%976%5C1%2B6%C3%978%5C1%2B.%2B2006%C3%972008%5C1%E7%AD%89%E4%BA%8E%3F)
丨x+2丨+丨y-3丨=0 则x+y的值为 绝对值最小的有理数是?1×2\1+2×3\1+3×4\1+.+n(n+1)=2×4\1+4×6\1+6×8\1+.+2006×2008\1等于?
丨x+2丨+丨y-3丨=0 则x+y的值为 绝对值最小的有理数是?1×2\1+2×3\1+3×4\1+.+n(n+1)=
2×4\1+4×6\1+6×8\1+.+2006×2008\1等于?
丨x+2丨+丨y-3丨=0 则x+y的值为 绝对值最小的有理数是?1×2\1+2×3\1+3×4\1+.+n(n+1)=2×4\1+4×6\1+6×8\1+.+2006×2008\1等于?
丨x+2丨+丨y-3丨=0 则x+y的值为-2+3=1
绝对值最小的有理数是0
1×2\1+2×3\1+3×4\1+.+n(n+1)
=1-1/2+1/2-1/3+……+1/n-1/(n+1)
=1-1/(n+1)
=n/(n+1)
2×4\1+4×6\1+6×8\1+.+2006×2008\1
=(1/2-1/4+1/4-1/6+……+1/2006-1/2008)÷2
=(1/2-1/2008)÷2
=1003/4016
因为丨x+2丨+丨y-3丨=0
所以x+2=0,y-3=0,
所以x=-2,y=3
则x+y的值为1,
绝对值最小的有理数是0
1×2\1+2×3\1+3×4\1+......+n(n+1)
=1-/2+1/2-1/3+1/3-1/4+...1/n-1/(n+1)
=1-1/(n+1)
=n/(n+1)
2×4\1...
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因为丨x+2丨+丨y-3丨=0
所以x+2=0,y-3=0,
所以x=-2,y=3
则x+y的值为1,
绝对值最小的有理数是0
1×2\1+2×3\1+3×4\1+......+n(n+1)
=1-/2+1/2-1/3+1/3-1/4+...1/n-1/(n+1)
=1-1/(n+1)
=n/(n+1)
2×4\1+4×6\1+6×8\1+.....+2006×2008\1
=(1/2)(1/2-1/4+1/4-1/6+1/6-1/8+..1/2006-1/2008)
=(1/2)(1/2-1/2008)
=1003/4016
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1
绝对值最小的有理数是 1
1×2\1+2×3\1+3×4\1+......+n(n+1)=
1/(1*2)=1/1-1/2
+ +
1/(2*3)= 1/2-1/3
+ +
1/(3*4)= 1/3-1/4
+ +
…...
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绝对值最小的有理数是 1
1×2\1+2×3\1+3×4\1+......+n(n+1)=
1/(1*2)=1/1-1/2
+ +
1/(2*3)= 1/2-1/3
+ +
1/(3*4)= 1/3-1/4
+ +
… …
+ +
1/[n(n-1)]=1/(n-1)-1/n
+ +
1/[n(n+1)]= 1/n-1/(n+1)
原式=1/1-1/(n+1)
=n/(n+1)
2×4\1+4×6\1+6×8\1+.....+2006×2008\1等于
1/2*4=(1/2-1/4)/2
1/4*6=(1/4-1/6)/2
1/6*8=(1/6-1/8)/2
……
1/2006*2008=(1/2006-1/2008)/2
所以,
原式=(1/2-1/4+1/4-1/6+1/6-1/8+…+1/2006-1/2008)/2
=(1/2-1/2008)/2=1003/4016
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