lg5+lg10= lg5+lg10=lg(5*10)=lg50,查表可得结果lg5+lg10=lg(5*10)=lg50=约1.2 lg5+lg10=lg(10/2)+1=1-lg2+1=2-lg2
logorithm of ten 還是lg10
log5+log5+log4=log(5*5*4)=log100=2 you see? result:log4=2-2*a2-2a log5+log4=log(5*5*4)=log100=2 =log