1、
log12 (3)=a,
則log3(12)=1/a,
log√3(√12) =1/a,
log√3(2√3) =1/a,
log√3(2)+ log√3(√3)=1/a,
log√3(2)+1=1/a,
log√3(2) =1/a-1,
所以log√3( 8)=3 log√3(2) =3/a-3.
2、
log2( 6) *lg0.125 +lg (27/125)
=lg6/lg2 * lg(1/8) +lg ((27×8)/1000)
= lg6/lg2 *(-3lg2) +lg(27×8)-3
=-3 lg6+3lg6-3
=-3.