1.(a-1)(a^2+a+1) 2.(m-1)(m+1)(m^2-1) 3.已知a-b=1/5,a^2+b^2=2又1/25,求(ab)^2007.4.不等式,(2x+1)/3≤负的六分之x+5 5.已知方程kx+1=2x-1的根是正数,则k的取值范围是?
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![1.(a-1)(a^2+a+1) 2.(m-1)(m+1)(m^2-1) 3.已知a-b=1/5,a^2+b^2=2又1/25,求(ab)^2007.4.不等式,(2x+1)/3≤负的六分之x+5 5.已知方程kx+1=2x-1的根是正数,则k的取值范围是?](/uploads/image/z/5328827-35-7.jpg?t=1.%EF%BC%88a-1%29%28a%5E2%2Ba%2B1%29+2.%EF%BC%88m-1%29%28m%2B1%29%28m%5E2-1%29+3.%E5%B7%B2%E7%9F%A5a-b%3D1%2F5%2Ca%5E2%2Bb%5E2%3D2%E5%8F%881%2F25%2C%E6%B1%82%EF%BC%88ab%29%5E2007.4.%E4%B8%8D%E7%AD%89%E5%BC%8F%2C%EF%BC%882x%2B1%29%2F3%E2%89%A4%E8%B4%9F%E7%9A%84%E5%85%AD%E5%88%86%E4%B9%8Bx%2B5+5.%E5%B7%B2%E7%9F%A5%E6%96%B9%E7%A8%8Bkx%2B1%3D2x-1%E7%9A%84%E6%A0%B9%E6%98%AF%E6%AD%A3%E6%95%B0%2C%E5%88%99k%E7%9A%84%E5%8F%96%E5%80%BC%E8%8C%83%E5%9B%B4%E6%98%AF%3F)
1.(a-1)(a^2+a+1) 2.(m-1)(m+1)(m^2-1) 3.已知a-b=1/5,a^2+b^2=2又1/25,求(ab)^2007.4.不等式,(2x+1)/3≤负的六分之x+5 5.已知方程kx+1=2x-1的根是正数,则k的取值范围是?
1.(a-1)(a^2+a+1) 2.(m-1)(m+1)(m^2-1) 3.已知a-b=1/5,a^2+b^2=2又1/25,求(ab)^2007.4.不等式,(2x+1)/3≤负的六分之x+5 5.已知方程kx+1=2x-1的根是正数,则k的取值范围是?
1.(a-1)(a^2+a+1) 2.(m-1)(m+1)(m^2-1) 3.已知a-b=1/5,a^2+b^2=2又1/25,求(ab)^2007.4.不等式,(2x+1)/3≤负的六分之x+5 5.已知方程kx+1=2x-1的根是正数,则k的取值范围是?
1.(a-1)(a^2+a+1) =a^3-1
2.(m-1)(m+1)(m^2-1)=(m^2-1)^2
3.已知a-b=1/5,a^2+b^2=2又1/25,求(ab)^2007.
a-b=1/5
(a-b)^2=a^2-2ab+b^2=1/25
a^2+b^2=2又1/25
2ab=(a^2+b^2)-(a^2-2ab+b^2)=2
ab=1
(ab)^2007=1
4.不等式,(2x+1)/3≤负的六分之x+5
不等式两边都乘以6,得 2(2x+1)≤-(x+5)
移项 2(2x+1)+(x+5)≤0
5x+7≤0
x≤-7/5
5.已知方程kx+1=2x-1的根是正数,则k的取值范围是?
kx+1=2x-1
kx-2x=-1-1
(k-2)x=-2
因为 x>0,所以k-2
1,2不明白要干什么,3题等于1,4题x小于等于负5分之3,5题k小于2
(a-1)(a^2+a+1)= (a-1)[a(a+1)+1]=a(a^2-1)+a-1=a^3-1
(m-1)(m+1)(m^2-1) =(m^2-1)(m^2-1)=m^4-2m^2+1