[-xx 5 4x] [5x-4 2xx]其中x=-2-搜答案-搜搜考试网

是这样的：x^5+x^4=x^3(x^2+x)=(x^2+x)[(x^3-1)+1]=(x^2+x)(x^3-1)+x^2+x=[x(x+1)(x-1)](x^2+x+1)+x^2+x=(x^3-x)

x-1/2x=421/2x=42x=84x-2/5x=3/83/5x=3/8x=3/8÷3/5x=5/8x+0.8x=361.8x=36x=2045-1/2x=51/2x=45-51/2x=40x=8

|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(1+2+...+9)=x(9-8-7-...-1)x=0记得采纳啊

2（x+5)^2-(x+6)^2-(x+2)(x-2)=422x²+20x+50-x²-12x-36-x²+4=428x=-12x=-3/2(2x+1)(x-3)-(2x

13x+42-5x=104-12x-22

13x+42-5x=104-12x-22把X都弄到一边,转换成13X-5X+12X=104-22-4220X=60得出X=3再问：如果是3两边好像不等啊？再答：不好意识，算错了，X=2，104-22-

5/9X+X=42

5/9X是5/9乘以x,还是5除以9x

4x+5x+14=42-2(x+3)

（4+5）X+14=42-2X-2*39x+14=(42-6)-2x9x+2x=42-6-1411x=22x=2

(x+7)(x+5)-(x+1)(x+5)=42(x+5)[(x+7)-(x+1)]=426(x+5)=42x+5=7x=2

提取公因式（x+5)6=42(x+5)=7所以x=2

（0.3+x)*2=80.3+x=8÷20.3+x=4x=4-0.3x=3.77+5x=425x=42-75x=35x=35÷5x=71.3x-x=18.60.3x=18.6x=18.6÷0.3x=6

5X+3（9-x)=375x+27-3x=375x-3x=37-272x=10x=542x+35(6-x)=23142x+35*6-35x=23142x-35x=231-35*67x=231-2107

x/x-3-5x/x^2-x-6计算

原式=[x/(x-3)]-[5x/(x²-x-6)]=[x/(x-3)]-(5x)/[(x-3)(x+2)]=[x(x+2)]/[(x-3)(x+2)]-(5x)/[(x-3)(x+2)]=

（x+7)(x+5)-(x+1)(x+5)=42(x+5)(x+7-x-1)=426(x+5)=42x+5=7x=2

#includesintjiesheng(intn)//用于计算阶乘如：3!{if(n=1)rerunn;returnn*hh(n-1)}doubledigui(intn,intx)//用以计算y=x

x-1/5x=324/5x=32x=32÷4/5x=40x+1/6x=427/6x=42x=42÷7/6x=36

X-1/5X=244/5x=24x=24÷4/5x30X-1/8X=427/8x=42x=42÷7/8x=48X-1/9X=648/9x=64x=64÷8/9x=72

/>(x+2)/(x+1)-(x+3)/(x+2)-(x+4)/(x+3)+(x+5)/(x+4)=1+1/(x+1)-1-1/(x+2)-1-1/(x+3)+1+1/(x+4)=1/(x+1)-1/

不太明白你的意思,是二个多项式通分同分母吗?(x+4)/(x^2+4x)=(x+4)/[x(x+4)]=1/x=(x-2)/[x(x-2)(x-5)/[x(x-5)-2(x-5)]=(x-5)/[(x