大师作文网7(x-12)=140
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12分之x+10=7X分之x+2解12分之x+10=7分之1X+212分之x=7分之1X+2-1012分之x=7分之1X-8
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550120x=550x=55/12=4.583
54+x=7x*(12+x)54+x=84x+7x^27x^2+83x-54=0方程的△明显是大于0的有2不等的根然后自己算啦!注意x不等于-12
18-5x=7x+12-5x-7x=12-18合并同类项得-12x=-6两边都除以-12得x=-6*(-1/12)x=1/2
5x/(x²+x-6)+(2x-5)/(x²-x-12)=(7x-10)/(x²-6x+8)5x/(x-2)(x+3)+(2x-5)/(x+3)(x-4)=(7x-10)
对不等式变形有[x-x^2+7x-12]/(x^2-7x+12)>=0,又因为x^2-7x+12=(x-3)(x-4)-x^2+8x-12=-(x-2)(x-6),于是有-(x-2)(x-3)(x-4
5x+35=140-2x5x+2x=140-357x=105x=159x-27=70+4x9x-4x=70+275x=97x=97/512+7x=2x+327x-2x=32-125x=20x=4250
(5-2x)/(x^2-x-12)=5x/(x^2+x-6)+(10-7x)/(x^2-6x+8)(5-2x)/(x-4)(x+3)=5x/(x+3)(x-2)+(10-7x)/(x-2)(x-4)分
x³-2x²-5x²+4x+12=0x²(x-2)-(5x²-4x-12)=0x²(x-2)-(5x+6)(x-2)=0(x-2)(x&su
解方程x=25x/28+9,得3x/28=9,得x=84
7x-x²=12x²-7x+12=0(x-3)(x-4)=0x1=3,x2=4
7x-2(x+4)=127x-2x-8=125x=12+8=20x=4
应该是-2x²,不是-3x²3x²-x=1原式=9x^4-3x³+15x³-5x²+3x²-7x+2001=3x²(3x
左右都乘以77x+84=15x+36,解得x=6
5x/(x²+x-6)+(2x-5)/(x²-x-12)=(7x-10)/(x²-6x+8)5x/[(x+3)(x-2)]+(2x-5)/[(x-4)(x+3)]=(7x
1/6x+1/12x+1/7x+5+1/2x+4=x2/12x+1/12x+6/12x-12/12x+1/7x=-9-1/4x+1/7x=-9-7x+4x=-9*28-3x=-9*28x=84
=x^2+10x-24+x^2+15x+56-x^2+5x+50=x^2+30x+82=4+60+82=146其实,不化简,直接代入=14*0+9*10+7*8=0+90+56=146也很简单
#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
7x-2x=1405x=140x=140除以5x=28