lg 125 +lg 8 = ?
log2 56 - log2 7=?
(紧挨着log的是底数)
1
=lg1000=3
2
=log2 8=3
lg 125 +lg 8 = lg125*8=lg1000=100
log2 56 - log2 7=1og2 56/7=log2 8=3