1÷7x

(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-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|

（x²+7x+10）/（x²+6x+5）×（x³+1）/（x²+4x+4）÷（x²-x+1）/(x-2)=（x+2)(x+5)/（x+5)(x+1)×

3x+7>13x>-6x>-2所以x=-1原式=(x²-4-x²+x)/x(x-2)÷(x-4)/(x-2)²=(x-4)/x(x-2)×(x-2)²/(x-4

解题思路：分式的混合运算，按照分式运算法则进行计算。解题过程：

分数W反了吧换位1/（10）-1/（9）=1/（7）-1/（-6）通过共享：1/（X-9）（X-10）=1/（X-7）（X-6）（X-9）（X-10）=（-7）（X-6）X^2-19X+90=X^2-

x^2*x^3+x^7÷x²=x^5+x^5=2x^5、【（x-y)²+（x+y)(x-y)]÷2x=(x-y)(x-y+x+y)÷2x=(x-y)*2x÷2x=x-y

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

(x+7)(x+6)-(x-2)(x+1)=x^2+13x+42-x^2+x+2=14x+44=2(7x+22)

先化简去掉中括号：(1-x+x-1/x)÷(1-1/x-1)再化简：(1-1/x)÷(-1/x)=(1-1/x)x(-x)=1-x

原式=[(3x^4+3x²)-(11x³+11x)+(2x²+2)+2x+5]÷(x²+1)=3x²-11x+2+(2x+5)/(x²+1)

(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)

已知x/(x²+3x+1)=1/7,求x²/(x⁴+3x²+1)的值【原题分母上的3x似乎是3x²之误】因为x/(x²+3x+1)=1/[

应该是-2x²,不是-3x²3x²-x=1原式=9x^4-3x³+15x³-5x²+3x²-7x+2001=3x²(3x

(2-x)/(x²-9)[1+(2x-7)/(x²-4x+4)]÷1/(x+3)=(2-x)/[(x+3)(x-3)](x²-2x-3)/(x-2)²×(x+3

原式化简：{（x-3)(x-2)/(x-3)(x-4)}²÷{(x+1)(x+2)/(x-4)(x+2)}²{(x-2)/(x-4)}²÷{(x+1)/(x-4)}

136487259875239146942615837693572418584961372217348695468753921359126784721894563

设这个数为X则：5X+0.5=505X=49.5X=9.9再答：3.32.8/(7+1)=4.14.设这个数是X45%X+3.6=12.6X=205.圆的周长为2πr=2*3.14*2=12.56则正

x(2-1/x)+x/(x^2-2x)÷(3-x)/(x^2-4)=x((2x-1)/x)+x/(x^2-2x)x(x^2-4)/(3-x)=(2x-1)+(x+2)/(3-x)=(7x-3-2x^2

=(x-2)/(x+3)(x-3)×(x²+2x-3)/(x-2)²×(x+3)/(x+1)=(x-2)/(x+3)(x-3)×(x-3)(x+1)/(x-2)²×(x+