化简求值 (1g2)^3+(1g5)^3+31g21g5

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化简求值 (1g2)^3+(1g5)^3+3*1g2*1g5
化简求值 (1g2)^3+(1g5)^3+3*1g2*1g5

化简求值 (1g2)^3+(1g5)^3+3*1g2*1g5
(1g2)^3+(1g5)^3+3*1g2*1g5
=(lg2+lg5)[(lg2）²-lg2lg5+（lg5）²]+3lg2lg5
=lg10[(lg2）²-lg2lg5+（lg5）²]+3lg2lg5
=(lg2）²-lg2lg5+（lg5）²+3lg2lg5
=(lg2）²+2lg2lg5+（lg5）²
=(lg2+lg5)²
=（lg10）²
=1²
=1

那个15级是对的

(1g2)^3+(1g5)^3+31g2*1g5
＝(lg2+lg5)[(lg2)^2+(lg5)^2-lg2lg5]+31g2*1g5
=[(lg2)^2+(lg5)^2-lg2lg5]+31g2*1g5
=[(lg2)^2+(lg5)^2+2lg2lg5]
=(lg2+lg5)^2
=1

前面回答的都正确

化简求值 (1g2)^3+(1g5)^3+3*1g2*1g5 (1g2)^3+(1g5)^3+31g2*1g5=? 解(1g2)^3+(1g5)^3+1g5*1g8 1g5^2+1g8^(2/3)+1g5·1g20+(1g2)^2= (1g5)+21g2-(1g2) 1g2+1g5= 1g2+1g5等于 1g2+1g5+(-8)的-1/3次方过程在此可以跟我解释一下,1g2+1g5怎么算 1g25+2/3g8+1g5乘1g20+(1g2)的平方 lg5+lg2*1g5+(1g2)^2 1g5-1g2份之一计算 1g5+1g2等于多少. 已知a+b=(1g2)^3+(1g2)^5+31g2*1g5,求3ab+a^3+b^3的值已知a+b=(1g2)^3+(1g2)^5+31g2*1g5,求3ab+a^3+b^3的值求值:1g8+1g125-1g2-1g5/1g根号下101g0.1等于 (1g2)的二次方+1g20乘以1g5 计算(1g5)2+1g2*1g50=多少? 计算2sin180°-1g5-1g2?有急用