log2(1/8)-lg1+2lg(1/3)+lg9=-3log2(2)-(lg1-2lg(1/3)-lg9)=-3-(lg1-lg9-lg(1/9))=-3-(lg(1/9)-lg(1/9))=-3
log2 八分之一–lg 1+2lg三分之一+lg9
log2(1/8)-lg1+2lg(1/3)+lg9=-3log2(2)-(lg1-2lg(1/3)-lg9)=-3-(lg1-lg9-lg(1/9))=-3-(lg(1/9)-lg(1/9))=-3