(lg2)^3+(lg5)^2=

(lg2)^3+(lg5)^2=
(lg2)^3+(lg5)^2=

(lg2)^3+(lg5)^2=
题目没问题?貌似只看过这类的：(lg2)^3+(lg5)^3+3lg5*lg2
a³+b³=(a+b)(a²-ab+b²) (lg2)^3+(lg5)^3+3lg5*lg2 =(lg2+lg5)[(lg2)²-lg2*lg5+(lg5)²]+3lg2*lg5 =(lg10)[(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 =(lg10)² =1² =1