3x²+6x-1＝0

(x+1-1/1-x)÷(x-x²/x-1)=[(x+1)+1/(x-1)]×[-(x-1)/x(x-1)]=(x²-1+1)/(x-1)×(-1/x)=-x/(x-1)(x-4/

x*x+x+1=0(x-1)(x*x+x+1)=0x^3-1=0x^3=1x^7+2x^6+x^5+x^4+x^3+x*x+1=x^6*x+2x^6+x^3*x^2+x^3*x+x^3+x*x+1=x

4/(x-2)+(x-1)/[(x-2)(x-3)]-2/(x-3)=0[4(x-3)+(x-1)-2(x-2)]/[(x-2)(x-3)]=03(x-3)/[(x-2)(x-3)]=0不知道解了~~

|x-1|+|x-10|表示数轴上x到1的距离+x到10的距离.显然最小值是9,此时x只要在1到10之间就好.类似的,|x-2|+|x-9|的最小值是7,此时x在2到9之间就好.|x-3|+|x-8|

x+x^2+x^3+x^4+x^5+x^6+x^7+x^8=（x+x^2+x^3+x^4）+（x^5+x^6+x^7+x^8）=x（1+x+x^2+x^3）+x^5（1+x+x^2+x^3）=（x+x

3x*x=1+x得6x*x*x+7x*x-5x+2000=3x^2*2x+7x^2-5x+2000=(1+x)2x+7x^2-5x+2000=9x^2-3x+2000=3(3x^2-x)+2000=3

中间错了原式=(x+2)/(x-3)(x+2)+2x/x(x-3)-(x+1)/(x-3)²=1/(x-3)+2/(x-3)-(x+1)/(x-3)²=3/(x-3)-(x+1)/

注意：本题x=2时题目没意义,应该舍去（这是很多学生错误所在）这里x只能取根号2-1  

∵2x²－6x－﹙1/2﹚˜²＝0∴x²-3x=1/8(x²－3x)/(x⁴－6x³＋9x²)=(x²-3x

3x^3-[x^3+(6x^2-7x)]-2(x^3-3x^2-4x)=3x^3-(x^3+6x^2-7x)-2x^3+6x^2+8x=3x^3-x^3-6x^2+7x-2x^3+6x^2+8x=15

1+x+x^2+x^3=0x+x^2+x^3+x^4+x^5+x^6+x^7+x^8=(x+x^2+x^3+x^4)+(x^5+x^6+x^7+x^8)=x(1+x+x^2+x^3)+x^5(1+x+

x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6)x/(x-2)=2x/(x-3)+(1-x)/(x-2)(x-3)x(x-3)/(x-2)(x-3)=2x(x-2)/(x-2)(x-3)

原式=(x+2)/(x+2)(x-3)-2x/x(x-3)-(x+1)/(x-3)²=1/(x-3)-2/(x-3)-(x+1)/(x-3)²=-1/(x-3)-(x+1)/(x-

有种方法叫做穿针引线法,需要在纸上画出函数的简图,这个题的答案应该是-2,3,6,1

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x（x*x-1)+x(5-x*x)-6y+7=-x+5x-6y+7=2(2x-3y)+7=2*(-4)+7=-8+7=-1再问：能在写详一点吗-x+5x-6y+7再答：x（x*x-1)+x(5-x*x

1,应该是x是几次幂就有几个根吧,所以应该是7+2=9个2.-7.036622145,-6.489288572,-6.200988153,-4.734373320,-4.289168546,-2.77

3≤|8-x|平方得：x^2-16x+55≥0(x-5)(x-11)≥0x≥11,x≤5|x+1|>2-x分类当x>-1时,x+1>2-x,x>1/2当x1/2|x+3|

x²-3x+1=0即有x+1/x=3所以x²+1/x²=x²+1/x²+2-2=(x+1/x)²-2=9-2=7再答：X²+3X+

=x^2002(x^4+x^3+x^2+x+1)=0提取公因式就行了