巧算(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)巧算:(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)(1+0.228-0.21)*(0.228-0.21+0.20030)-(1+0.228-0.21+0.2003)*(0.228-0.21)解方程:7(x-3)=9+X21-x=1.5(9+x)
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巧算(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)巧算:(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)(1+0.228-0.21)*(0.228-0.21+0.20030)-(1+0.228-0.21+0.2003)*(0.228-0.21)解方程:7(x-3)=9+X21-x=1.5(9+x)
巧算(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)
巧算:
(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)
(1+0.228-0.21)*(0.228-0.21+0.20030)-(1+0.228-0.21+0.2003)*(0.228-0.21)
解方程:
7(x-3)=9+X
21-x=1.5(9+x)
巧算(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)巧算:(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)(1+0.228-0.21)*(0.228-0.21+0.20030)-(1+0.228-0.21+0.2003)*(0.228-0.21)解方程:7(x-3)=9+X21-x=1.5(9+x)
(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)
=(3/2)×(4/3)×(5/4)×……×(2003/2002)×(2004/2003)
=1002
设0.228-0.21=x 0.228-0.21+0.2003=y
原式=(1+x)y - (1+y)x = y + xy - x - xy = y - x =0.2003
7(x-3)=9+X
7x-21=9+x
6x=30
x=5
21-x=1.5(9+x)
21-x=13.5+1.5x
-2.5x=-7.5
x=3
1题:=3/2*4/3....2004/2003=1002
2ti: =0.228-0.21=0.018
3ti: x=5
4ti: x=3
(2-1/2)*(2-2/3)*(2-3/4)*......*(2-2002/2003)
=(3/2)(4/3)(5/4)……(2003/2002)(2004/2003)
=2004/2
=1002
21-x=1.5*(9+x)
21-x=13.5+1.5x
-2.5x=-7.5
x=3
(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)=3/2*4/3*5/4*6/5....*2004/2003=1002
7(x-3)=9+X 7x-21=9+x 6x=30 x=5
21-x=1.5(9+x) 21-x=13.5+1.5x x=3
(1+0.228-0.21)*(0.228-0.21+0.20030)-(...
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(2-1/2)×(2-2/3)×(2-3/4)×……×(2-2002/2003)=3/2*4/3*5/4*6/5....*2004/2003=1002
7(x-3)=9+X 7x-21=9+x 6x=30 x=5
21-x=1.5(9+x) 21-x=13.5+1.5x x=3
(1+0.228-0.21)*(0.228-0.21+0.20030)-(1+0.228-0.21+0.2003)*(0.228-0.21)=(0.228-0.21+0.20030)+(0.228-0.21)(0.228-0.21+0.20030)-
(0.228-0.21)-(0.228-0.21+0.2003)(0.228-0.21)=0.20030
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