超级大房东
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共回答了22个问题采纳率:86.4% 举报
(x^2+7x+10)/(x^2+6x+5)×(x^3+1)/(x^2+4x+4)÷(x^2-x+1)/(x+2)
=(x+2)(x+5)/(x+1)(x+5)*(x+1)(x^2-x+1)/(x+2)^2÷(x^2-x+1)/(x+2)
=(x+2)(x+5)/(x+1)(x+5) * (x+1)(x^2-x+1)/(x+2)^2 * (x+2)/(x^2-x+1)
=1
1年前
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超级大房东
x^3+1=(x+1)(x^2-x+1) 依据:立方和公式,a^3+b^3=(a+b)(a^2-ab+b^2) x^2+4x+4=(x+2)^2即(x+2)² 依据:完全平方公式,(a+b)^2=a^2+2ab+b^2逆用