(lg2)³+(lg5)³+3lg2*lg5=

来源：学生作业帮编辑：作业帮分类：综合作业时间：2024/10/03 02:40:59

lg2+lg5=1
(lg2)³+(lg5)³+3lg2*lg5
= (lg2+lg5)[(lg2)²-lg2*lg5+(lg5)²]+3lg2*lg5
=(lg2)²-lg2*lg5+(lg5)²+3lg2*lg5
=(lg2)²+2lg2*lg5+(lg5)²
=(lg2+lg5)²
=1²
=1

(lg2)³+3lg2*lg5+(lg5)³等于多少（lg2）³+（lg5）³+3lg5lg2=? lg2^2+lg2*lg5+lg5=lg2(lg2+lg5)+lg5 1.lg²5+lg2×lg5+lg2 2.（lg2）³ +（lg 5）³ +3lg 2×l lg5+lg5*lg2+lg2*lg2 lg2(lg5-lg2)-lg5(lg5+3lg2)等于 (lg5)^2+lg5.lg2= 1.（lg2）^3+(lg5)^3+3lg2*lg5= (lg2)³+(lg5)³+3lg2×lg5=? (lg2)^3+(lg5)^3+3*lg2*lg5 (lg2)^2+lg2*lg5+(lg5)^2= (lg2)³+(lg5)³+3lg2×lg5