x2-2kx k 20=0
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原式=-x-2,当x=12时,原式=-12-2=-212.
x^2+3x-2=0,x(x+3)=2,∴(2x-4)╱(x^2+6x+9)÷(x-3)×(x^2-9)╱(2x-x^2)=2(x-2)/(x+3)^*1/(x-3)*(x+3)(x-3)/[x(2-
应该是求-x³+2x²+2008x²=x+1所以x³=x²*x=(x+1)x=x²+x=(x+1)+x=2x+1所以-x³+2x&
原式可化为1/(x+1)(x-3)+2/(x-3)((x+2)+3/(x+1)(x+2)=0两边同乘以:(x+1)(x+2)(x-3)得:(x+2)+2(x+1)+3(x-3)=0(x≠-1,x≠-2
直接写答案?再问:要写过程,再答:好了哦,给采纳一下吧
(x²-2x)+(x²-2x)-2=0(x²-2x+2)(x²-2x-1)=0∵x²-2x+2=(x-1)²+1>0∴x²-2x-
(x²+y²)²+(x²+y²)-6-6=0(x²+y²)²+(x²+y²)-12=0(x²
有韦达定理得x1+x2=2mx1*x2=m+2则(x1)²x2+x1(x2)²=x1*x2(x1+x2)=2m(m+2)=0解得m=0或-2当m=-2时,x^2+4x=0,有两个实
x1,x2是方程的根,所以满足x1²-x1-4=0,x2²-x2-4=0x1³-x1²-4x1=0,所以x1³=x1²+4x1x1³
再问:ˉX2+X+30=0再问:X2-3X-4=0再问:
X1+X2+X3=0①2X2-X3=1②X1-X2+2X3=-1③①+②:X1+3X2=1∴X1=1-3X2代入①,得:1-2X2+X3=0∴X3=2X2-1∴X1=1-3t,X2=t,X3=2t-1
5x²-3x-5=0△=3²-4×5×(-5)=109x=[﹣(﹣3)±√109]/5由原方程可得所求式子=(x+5)-1/(x+5)所求式子=(118±6√109)/25-25/
由柯西不等式得:【x1^2/(x1+x2)+x2^2/(x2+x3)+x3^2/(x3+x1)】*【(x1+x2)+(x2+x3)+(x3+x1)】≥(x1+x2+x3)方所以x1^2/(x1+x2)
将式子通分得(x1²+x2²)÷x1x2=1.5,再整理得[(x1+x2)²-2x1x2]÷x1x2=1.5,而根据维达定理知x1+x2=2-k、x1x2=k-2,求出k
你好x²+3x-1=0两边同除以xx+3-1/x=0x-1/x=-3两边平方得x²+1/x²-2=9x²+1/x²=11x²+1/x
3x²-7x+2=0)3x-1)(x-2)=0x1=1/3,x2=2所以x1+x2=7/3
解题思路:利用一元二次方程计算解题过程:最终答案:略