lg5*lg5+2/3lg8+lg5*lg20求值,
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lg5*lg5+2/3lg8+lg5*lg20
求值,
(2/3)lg(8)=(2/3)lg(2³)=2lg2
则:
原式=[lg5]²+2lg2+lg5×[lg2+lg10]
. =[lg5]²+2lg2+lg5×[1+lg2]
. =[lg5]²+2lg2+lg5+lg2×lg5
. =lg5[lg2+lg5]+2lg2+lg5
. =lg5+2lg2+lg5
. =2lg5+2lg2
. =2[lg2+lg5]
. =2
这没法算啊。。
你题应该是打错了吧
应该是lg5²+(2/3)lg8+lg5*lg20+(lg2)²吧
lg5²+(2/3)lg8+lg5*lg20+(lg2)²
=lg5²+2/3lg8+lg5×lg20+(lg2)²
=2lg5+2/3lg2³+lg5×lg(4×5)+(lg2)...
全部展开
这没法算啊。。
你题应该是打错了吧
应该是lg5²+(2/3)lg8+lg5*lg20+(lg2)²吧
lg5²+(2/3)lg8+lg5*lg20+(lg2)²
=lg5²+2/3lg8+lg5×lg20+(lg2)²
=2lg5+2/3lg2³+lg5×lg(4×5)+(lg2)²
=2lg5+(2/3)×3lg2+lg5×(lg4+lg5)+(lg2)²
=2(lg5+lg2)+lg5×lg2²+(lg5)²+(lg2)²
=2lg(5×2)+2lg5×lg2+(lg5)²+(lg2)²
=2lg10+(lg5+lg2)²
=2+[lg(5×2)]²
=2+(lg10)²
=2+1²
=3
收起
lg5*lg5+2/3lg8+lg5*lg20求值,
lg8+3lg5=?
lg5^2+2/3lg8+lg5*lg20+lg2^2
lg5^2+2/3lg8+lg5*lg20+lg^2
lg5^2+lg8^2/3+lg5*lg20+(lg2)^2=?
(lg5)平方+2/3lg8+lg5乘lg20+(lg2)平方
3lg2+2lg5+lg5乘以lg8怎样算
lg5²+2/3lg8+lg5*lg20+(lg2)²
lg5²+2/3lg8+lg5×lg20+(lg2)²
lg5^2+2/3lg8+lg5*lg20+(lg2)^2 lg5*lg20怎么办啊
2lg5+2/3lg8等于
lg2+lg5=?1-lg2=?1-lg5=?2lg5+2/3lg8+lg5*lg20+(lg2)2=?
lg8+3 lg5等于多少
lg8+3lg5等于多少
lg8+3lg5=____?
lg8+3lg5的值?
lg8+3lg5怎么计算
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