（lg2）的平方+lg20×lg5答案,

（lg2）的平方+lg20×lg5答案,
（lg2）的平方+lg20×lg5答案,

（lg2）的平方+lg20×lg5答案,
(lg2)²+lg20×lg5=(lg2)²+(lg4+lg5)×lg5=(lg2)²+(2lg2+lg5)×lg5=(lg2)²+2lg2×lg5+(lg5)²=(lg2+lg5)²=(lg(2×5))²=1²=1

(lg2）的平方+lg20×lg5
=lg²2+(lg2+1)(1-lg2)
=lg²2+1-lg²2
=1

lg20=lg(2×10)=(lg10)+lg2=1+lg2
原式
=（lg2)²+(1+lg2)lg5
=(lg2)²+(lg2)(lg5)+lg5
=(lg2+lg5)(lg2)+lg5
=[lg(2×5)](lg2)+lg5
=lg2+lg5
=lg(2×5)
=1

(lg2)² + lg20×lg5
= (lg2)² + lg(4×5)×lg5
= (lg2)² + lg4×lg5 + (lg5)²
= (lg2)² + lg2²×lg5 + (lg5)²
= (lg2)² + 2×lg2×lg5 + (lg5)²
= (lg2 + lg5)²
= {lg(2×5)}²
= {lg10}²
= 1

lg平方5+lg2*lg5+lg20怎么算? 问题补充：还有 7lg20*(1/2)上面的lg0.7 10。把前两项的lg5提出来，得：lg5(lg2+lg5)+lg20=lg10 *