简便方法的题1-2/3-2/9-2/27-2/81-2/243-2/729 76x（1/23-1/53）+23x（1/5

1-2/3-2/9-2/27-2/81-2/243-2/729 76x（1/23-1/53）+23x（1/53+1/76）-53x（1/23-1/76）=1/3-2/9-2/27-2/81-2/243-2/729 =76/23-76/53+23/53+23/76-53/23+53/76=1/9-2/27-2/81-2/243-2/729 =（76/23-53/23）+（23/53-76/53）+（23/76+53/76）=1/27-2/81-2/243-2/729 =1-1+1=1/81-2/243-2/729 =1=1/243-2/729=1/72999999x77778+33333x66666 0.01992/0.004X1/2000 =99999x77778+33333x3x22222 =(0.01992/0.004)X1/2000=99999x(77778+22222) =123/5x1/2000=99999x100000 =123/10000=9999900000 1-1/10-1/100-1/1000-.1/10000000000 =1-(0.1+0.01+0.001+0.0001.+0.00000000001 =1-0.11111111111=0.88888888889 18/5÷2.4-2.25×2/3+（804-10.5x0.8）÷5.75 =18/5÷12/5-9/4×2/3+(804-8.4)÷23/4=3/2-3/2+3978/5÷23/4=15912/1151÷（20.08x37-200.8x1.9+2008x0.82）x1/2008=1÷（2008x0.37-2008x0.19+2008x0.82）x1/2008=1÷2008x（0.37-0.19+0.82）x1/2008=1÷(0.37-0.19+0.82)=1÷1=119.98x37-199.8x1.9+1998x0.82=1998x0.37-1998x0.19+1998x0.82=1998x(0.37-0.19+0.82)=1998x1=1998