2x平方减4x减1等于0
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(2x减1)的平方等于x的平方加4x加4(2x-1)^2=x^2+4x+44x^2-4x+1=x^2+4x+43x^2-8x-3=0(3x+1)(x-3)=03x+1=0x1=-1/3x-3=0x2=
2x的平方减5x等于0x(2x-5)=0x=0或2.5和4x的平方=x-1的平方4x的平方=x的平方-2x+13x的平方+2x-1=0(3x-1)(x+1)=0x=-1或1/3
x^2-4x+1=0易证x≠0等式两边除以x得x-4+1/x=0x+1/x=4(x+1/x)^2=16x^2+2+1/x^2=16x^2-2+1/x^2=12(x-1/x)^2=12x-1/x=±2√
x的n次方记作x^n.由方程得1=4x-x^2,x^2+1/x^2=x^2+(4x-x^2)/x^2=x^2+4/x-1=x^2+(16x-4x^2)/x-1=x^2+16-4x-1=x^2-4x+1
x²+x-²=14
用十字相乘法(把二次项系数和常数项分解成两个数的乘积,然后再交叉相乘,只要得一次项系数可应以了.)先对左边因式分解.得(x-3)(x2)=0,解得x=-3和x=2呵呵,我昨天才出了这个题给我学生做的.
解题思路:利用一元二次方程根的判别式求解。解题过程:解:∵x2-2x+4=0∴△=(-2)2-4×1×4=4-16=-12<0∴此方程无解最终
x²+2x-1=0两边同时除以xx+2-1/x=0x-1/x=-2再问:X的平方+1/X的平方再答:(x-1/x)²=4x²+1/x²-2=4x²+1
由x²+2x-1=0两边同除x:x+2-1/x=0,∴x-1/x=-2,(x-1/x)²=(-2)²x²-2+1/x²=4,即x²+1/x&
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2x^2-3x+1=0(2x-1)(x-1)=02x-1=0x=1/2x-1=0x=1
(x-3)²+4x(x-3)=0(x-3)[(x-3)+4x]=0(x-3)(5x-3)=0x1=3,x2=3/59(x-2)²=4(x+1)²3(x-2)=2(x+1)
2x²-3x+1=0∴4x²-6x+2=0∴4x²-6x=-24x²-6x-5=-2-5=-7
x²-4x-1=0x²-4x=1所以:(2x-3)²-(x+y)(x-y)-y²=4x²-12x+9-(x²-y²)-y²
2x^2-4x=12x^2-4x-1=02(x^2-2x+1)-3=0(x-1)^2=3/2x=√3/2+1
x²-2x-1=0x²-2x+1-2=0(x-1)²=2x-1=±√2x1=1+√2x2=1-√2
(x-2)²-4(x+1)²=0平方差公式:[(x-2)+2(x+1)][(x-2)-2(x+1)]=03x(-x-4)=0x(x+4)=0x=0或x=-4
4x²+3x-2=0△=9+4×2×4=41x=(-3±√41)/8再问:△=9+4×2×4=41这个是哪里来的呀如果这是一道问答题那它有没有实数解,有几个解再答:△=9+4×2×4=41>