计算(1/2001-1/2002)-(1/2003-1/2002)-(1/2001-1/2003)已知A,B,C,D,四个数,其中A的绝对值等于0.5,且A比-0.1大,B比-1/4小3,C的倒数为4/11,D的相反数与2的差为-9又2分之一.(1)求A,B,C,D;(2)计算-A-B+C-D的值.观察
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计算(1/2001-1/2002)-(1/2003-1/2002)-(1/2001-1/2003)已知A,B,C,D,四个数,其中A的绝对值等于0.5,且A比-0.1大,B比-1/4小3,C的倒数为4/11,D的相反数与2的差为-9又2分之一.(1)求A,B,C,D;(2)计算-A-B+C-D的值.观察
计算(1/2001-1/2002)-(1/2003-1/2002)-(1/2001-1/2003)
已知A,B,C,D,四个数,其中A的绝对值等于0.5,且A比-0.1大,B比-1/4小3,C的倒数为4/11,D的相反数与2的差为-9又2分之一.
(1)求A,B,C,D;
(2)计算-A-B+C-D的值.
观察下列各式:1/2+1=1-1/2,1/2×3=1/2-1/3,1/3×4=1/3-1/4,```请你将猜想到的规律用正整数N表示出来,并计算1/2-1/6-1/12-``````1/462的值.
计算(1/2001-1/2002)-(1/2003-1/2002)-(1/2001-1/2003)已知A,B,C,D,四个数,其中A的绝对值等于0.5,且A比-0.1大,B比-1/4小3,C的倒数为4/11,D的相反数与2的差为-9又2分之一.(1)求A,B,C,D;(2)计算-A-B+C-D的值.观察
(1/2001-1/2002)-(1/2003-1/2002)-(1/2001-1/2003) =1/2001-1/2002-1/2003+1/2002-1/2001+1/2003=1/2001-1/2001-1/2002+1/2002-1/2003+1/2003=0
因A>-0.1,所以A=0.5 B=-1/4-3=-13/4
C=1 / 4/11 =11/4
D=-(-19/2+2)=15/2
-A-B+C-D=-1/2+13/4+11/4-15/2=-2
因1/2+1=1-1/2,1/2×3=1/2-1/3,1/3×4=1/3-1/4,
所以1/N * (N+1) = 1/N- 1/(N+1)
1/2-1/6-1/12-``````1/462=1/2-(1/2-1/3)-(1/3-1/4)-`````-(1/23-1/24)=1/2-1/2+1/3-1/3+1/4-`````-1/21+1/22=1/22
A=0.5.B=-3又1/4.C=11/4.D=7又1/2.
-A-B+C-D
=-0.5-(-3又1/4)+11/4-7又1/2
=0.5+3又1/4+11/4-7又1/2
=0.5+3.25+2.75-7.5
=6.5-7.5
=-1
我只知道第一题,不好意思啊
da
A=0.5.B=-3又1/4.C=11/4.D=7又1/2.
-A-B+C-D
=-0.5-(-3又1/4)+11/4-7又1/2
=0.5+3又1/4+11/4-7又1/2
=0.5+3.25+2.75-7.5
=6.5-7.5
=-1