lg25+2/3*lg8+lg5*lg20+lg22=2lg5+2/3*3lg2+lg5*(lg5+lg4)+lg22=2lg5+2lg2+(lg5)^2+2lg5*lg2+lg22=2(lg5+lg2)+(lg5+lg2)^2-(lg2)^2+lg22=2+1+lg22-(lg2)^2=3+lg22-(lg2)^2 约为4.2518036225327
