第845题：对数公式练习
计算A,B
lg5+lg20\lg {\sqrt{5}} + \lg {\sqrt{20}} lg√5+lg√20 =A= A=A
2log510+log50.252 \log_5 10 +\log_5 0.25 2log510+log50.25 =B=B=B
logaMn=nlogaM\log_a M^n = n \log_a MlogaMn=nlogaM
