Question

写出计算过程和用到的公式

Answer 1

原式=(lg2³+lg5³-lg2-lg5)/[lg10的1/2次方*lg(1/10)]-(log4 4/log4 5) *log4 5-0

=(3lg2-lg2+3lg5-lg5)/[(1/2)lg10*(lg1-lg10)]-1

=2(lg2+lg5)/[(1/2)*1*(0-1)]-1

=2lg(2*5)/(-1/2)-1

=-4lg10-1

=-4*1-1

=-4-1

=-5.

loga 1=0

loga a=1

loga (b*c)=loga b+loga c

loga (b/c)=loga b-loga c

loga b的m次方=mloga b;

换底公式 ：loga b=logc b/(logc a);