Question

问一道高中数学计算题lg25+2\3lg8+lg5xlg20+(lg2)^2关键是那个lg5乘lg20怎么算?

Answer 1

原式等于2lg5+2/3 3lg2+lg5(lg5+lg4)+(lg2)^2=2lg5+2lg2+(lg5)^2+lg5*lg4+(lg2)^2=2lg5+2lg2+(lg5)^2+2lg5*lg2+(lg2)^2=2(lg5+lg2)+lg5(lg5+lg2+lg2)+(lg2)^2=2+lg5(1+lg2)+(lg2)^2=2+lg5+lg5*lg2+(lg2)^2=2+lg5+lg2...