Question

lg25+2\3lg8+lg5+lg²2等于多少

Answer 1

23lg8=lg 8^(2/3)=lg4所以上式等于

lg25+lg4+lg5+(lg2)^2=lg(25*4)+lg5+(lg2)^2=2+lg5+(lg2)^2=2+lg(10*0.5)+(lg2)^2=3+lg0.5+(lg2)^2

=3-lg2-(lg2)^2=3-lg2(1+lg2)=3-lg2*lg20