1/2lg25+lg2-lg根号0.1-log2(9)*log3(2)=1/2lg5^2+lg2-lg0.1^(1/2)-lg9/lg2*lg2/lg3=1/2*2*lg5+lg2-lg10^(-1/2)-2lg3/lg2*lg2/lg3=lg5+lg2-(-1/2)lg10-2=1+1/2-2=-1/2