简单对数运算lg5*lg20+(lg2)^2=?
问题描述:
简单对数运算
lg5*lg20+(lg2)^2=?
答
lg5*lg20+(lg2)^2
=lg5*(1+lg2)+lg2*lg2
=lg5+(lg5+lg2)*lg2(提公因式lg2)
=lg5+1*lg2
=1
答
lg5*lg20+(lg2)^2
=lg5*(lg2*10)+(lg2)^2
=lg5*(lg2+1)+(lg2)^2
=lg5*lg2+lg5+(lg2)^2
=lg2*(lg5+lg2)+lg5
=lg2*1+lg5
=1