2lg5+3分之2lg8+lg5乘lg20+(lg2)^2

来源：学生作业帮助网编辑：作业帮时间：2024/05/06 20:28:14

2lg5+3分之2lg8+lg5乘lg20+(lg2)^2
2lg5+3分之2lg8+lg5乘lg20+(lg2)^2

2lg5+3分之2lg8+lg5乘lg20+(lg2)^2
lg5^2+2/3lg8+lg5*lg20+(lg2)^2
=2lg5+2/3lg2^3+lg5*lg(4*5)+(lg2)^2
=2lg5+2lg2+(lg5)^2+lj5*2lg2+)lg2)^2
=2(lg2+lg5)+(lg2+lg5)^2
=2lg10+lg10^2
=2+1
=3

2lg5 +(2lg8)/3 +lg5*lg20 +(lg2)^2
=lg5[2+lg(2*10)]+2lg2+(lg2)^2
=lg5(3+lg2)+lg2(2+lg2)
=lg5 +(2+lg2)(lg5+lg2)
=lg5+lg2+2
=3

（lg5)平方+2/3lg8+lg5乘lg20+（lg2)平方 2lg5+3分之2lg8+lg5乘lg20+(lg2)^2 化简[(1-lg5)^2+lg2乘lg5]/lg8 lg5^2+2/3lg8+lg5*lg20+lg2^2 lg5^2+lg8^2/3+lg5*lg20+(lg2)^2=? 3lg2+2lg5+lg5乘以lg8怎样算 lg5²+2/3lg8+lg5*lg20+(lg2)² lg5²+2/3lg8+lg5×lg20+(lg2)² lg2+lg5=?1-lg2=?1-lg5=?2lg5+2/3lg8+lg5*lg20+(lg2)2=? lg5^2+2/3lg8+lg5*lg20+(lg2)^2 lg5*lg20怎么办啊 (lg2)^3+(lg5)^3+lg5*lg8=(lg2+lg5)[(lg2)^2-lg2*lg5+(lg5)^2]+lg5*lg2^3=1[(lg2)^2-lg2*lg5+(lg5)^2]+3lg5*lg2=(lg2)^2+(lg5)^2+2lg5*lg2=(lg2+lg5)^2=1网上看了看答案,可是第一步没有看懂.求得出第一步的过程, 对数lg2*lg5=?2lg（5）+2/3 lg8+lg5*lg20+lg2 =lg5^2+lg8^(2/3)+lg5*(lg4+lg5)+lg2 =lg100+lg5+2lg2*lg5+lg2 =2+(lg5+lg2) =2+1 =3 第二个等号lg5*(lg4+lg5)为什么=lg5+2lg2*lg5 lg5（2）+2/3lg8+lg5*lg2+（lg2）^2 计算：（lg2)2+3lg5+lg5(1+lg2)+lg8+log2（5）log5（4) 计算 lg25 + 2/3 lg8+lg5乘 lg20+(lg2)^2+lg100___. lg25+2/3lg8+lg5*lg20+(lg2)^2 （lg2）^2+lg25+2/3lg8+lg5*lg20=? lg25+2/3lg8+lg5*lg20+（lg2）^2=?