1/9{1/7[1/5((x+2)/3 +4)+6]+8}=1
1/7[1/5((x+2)/3 +4)+6]+8=9
1/7[1/5((x+2)/3 +4)+6]=1
1/5((x+2)/3 +4)+6=7
1/5((x+2)/3 +4)=1
(x+2)/3 +4=5
(x+2)/3 =1
x+2=3
x=1
(x-1.3)/2 -(8x-1.8)/1.2=(5x-0.4)/0.3 -x
1.2(x-1.3)-2(8x-1.8)=8(5x-0.4)-2.4x
1.2x-1.56-16x+3.6=40x-3.2-2.4x
52.4x=5.24
x=0.1
1-[ 1+1/2(1-x)]/3=4
[1+1/2(1-x)]/3=-3
1+1/2(1-x)=9
1/2(1-x)=8
1-x=16
x=-15
(0.4x+0.9)/0.5 -(0.03x+0.02)/0.03=(x-5)/2
6(0.4x+0.9)-100(0.03x+0.02)=1.5(x-5)
2.4x+5.4-3x-2=1.5x-7.5
2.1x=10.9
x=109/21=5又4/21
(0.1x-0.2)/0.02+(x+1)/5=-1
50(0.1x-0.2)+0.2(x+1)=-1
5x-10+0.2x+0.2=-1
5.2x=8.8
x=88/52=22/13=1又9/13
1/(1×2)+1/(2×3)+···+1/(2002×2003)+1/(2003×2004)+1/(2004×2005)
=1-1/2+1/2-1/3+...+1/2002-1/2003+1/2003-1/2004+1/2004-1/2005
=1-1/2005
=2004/2005