lg1/4-lg25
=lg(1/4)/25
=lg1/100
=-2
2log5 10+log5 0.25
=log5 10^2+log5 0.25
=log5 100+log5 0.25
=log5 100*0.25
=log5 25
=2
lg√3
=lg3^(1/2)
=(1/2)*lg3
=0.4771/2
=0.2386
lg3/2=lg3-lg2
=0.4771-0.3010
=0.1761
loga x=1/2loga b-loga c
loga x=loga b^(1/2)-loga c
loga x=loga b^(1/2)/c
x=b^(1/2)/c