方程x方-9x 18=0
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一般可化解为a(x-b)^2=c配方就行了..2(x-3/4)^2=17/8所以(x-3/4)^2=17/16楼主以你聪明的头脑一定会解了我只是提供下思路.
(-1加减根号下41)/2
x^4-x^3-3x-9=0(x²+3)(x²-3)-x(x²+3)=0(x²+3)(x²-x-3)=0x²+3=0无解x²-x-
(x+6)(x-36)=0x=-6或36
1)x^2+y^2-2(t+3)x+2(1-4t^2)y+16t^4+9=0[x-(t+3)]^2+[y+(1-4t^2)]^2=-7t^2+6t+1R^2=-7t^2+6t+1-7t^2+6t+1>
x=0显然不是根.两边同时除以x^2得:3x^2-2x-2-2/x+3/x^2=0令t=x+1/x则x^2+1/x^2=t^2-2代入方程得:3(t^2-2)-2t-2=03t^2-2t-8=0(3t
4x方+x+2x根号下(3x方+x)=[x+根号下(3x方+x)]的平方=9x+根号下(3x方+x)=33x方+x=(3-x)的平方=9-6x+x方2x方+7x=9x=1
1:(40/29-11/29)×18+92=1102:x=0,y=4;x=2,y=3;x=3,y=2;x=6,y=0就这些,负数你们用不到吧
无解再问:。。。我想多了,谢谢了哈
其实可以看出三个解是-1,2,3这样,如果题目给的区间没错的话设f(x)=(x+1)(x-2)(x-3)则求f(-1)和f(0)和f(-1/2)发现f(-1)=0,f(0)*f(-1/2)0,故方程(
戴尔他=(-2)^2+4=8x=(2+-2根号2)/2=1+-根号2
60x²+20x-31=060x²+20x=31两边同时除以60得x²+x/3=31/60x²+x/3+(1/6)²=1/36+31/60(x+1/6
x²+3x-2=0Δ=3²-4×1×(-2)=9+8=17∴x=(-3±√17)/2x1=(-3+√17)/2x2=(-3-√17)/2
x²-5x+4=0(x-4)(x-1)=0x=4或x=1
2006x方+2007x+1=0(2006x+1)(x+1)=0x1=-1/2006x2=-1
x=+-2
X方-2X-2=0x²-2x+1=3(x-1)²=3x-1=±√3x1=1+√3x2=1-√3
x²-2√3x=0x(x-2√3)=0x=0,x=2√33x²-6x=-3x²-2x+1=0(x-1)²=0x-1=0x=1
2x²-13x+20=0(x-4)(2x-5)=0x=4,x=5/2
1、2x²-x=0x(2x-1)=0∴x=0x=1/22、x²-x/2=1x²-x/2+1/16=17/16(x-1/4)²=17/16∴x=1/4+√17/4