(lg2)^3+(lg5)^2=
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![(lg2)^3+(lg5)^2=](/uploads/image/z/5178216-48-6.jpg?t=%28lg2%29%5E3%2B%28lg5%29%5E2%3D)
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(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