2x的平方减7x加6等于0
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应该是x^2-2x+y^2+6y+10=0配方:x^2-2x+1+y^2+6y+9=0(x-1)^2+(y+3)^2=0得x=1y=-3所以x+y=-2
x^2-2x+y^2+6y+10=0(x-1)^2+(y+3)^2=0(x-1)^2=0x-1=0x=1(y+3)^2=0y+3=0y=-3x+y=1-3=-2
x^2+6x-1=0用求根公式x=(-6±√36+4)/2x=-3±√10
解x²-6x+m=0(x²-6x+9)=9-m(x-3)²=9-m等价于(x-n)²=7∴m=2,n=3∴x²-6x+m=2∴x²-6x+2
x^2+2x+y^2-6y+10=0=(x^2+2x+1)+(y^2-6y+9)=0=(x+1)^2+(y^2-6y+3^2)=0=(x+1)^2+(y-3)^2=0x=-1y=3xy=-3
x^2-6x+9=(5-2x)^2x^2-6x+9=4x^2-10x+253x^2-4x+16=0x^2-4x/3+16/3=0(x-4/6)^2+16/3-16/36=0∵16/3-16/36>0∴
x^2-3x=57-2x^2+6x=7-2(x^2-3x)=7-2X5=7-10=-3
x^2-2x+y^2+6y+10=0x^2-2x+1+y^2+6y+9=0(x-1)^2+(y+3)^2=0x-1=0,y+3=0x=1,y=-3(x-y)/(x+y)=4/(-2)=-2
3x^2-7x+3=0等式两边同除x得3x-7+3/x=0即x+1/x=7/33x^2-7x+3=0(1)等式两边同除x^2得3-7/x+3/x^2=0(2)(1),(2)两式相加得3x^2+3/x^
第一个方程用十字相乘算出x=1,x=2代入第二个要求的方程,算一下38和154
x^2-3x+1=0x+1/x=(x^2+1)/x=(x^2-3x+1+3x)/x=(0+3x)/x=3x^2+1/x^2=(x+1/x)^2-2=3^2-2=7
2x^2-7x+6=0,(x-2)(2x-3)=0,x=2,x=3/2
2x^2-7x+3=0分解因式(x-3)(2x-1)=0所以x=1/2或x=3或者用公式法△=49-4×2×3=25x=(7+5)/4=3或x=(7-5)/4=1/2所以x=1/2或x=3
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
Δ=36-4=32x=2分之(6加减4根号2)x=3加减2根号2
6x²-7x+1=0(x-1)(6x-1)=0x=1,x=1/6再问:能详细一点吗谢谢再答:6x^2-6x-x+1=06x(x-1)-(x-1)=0(x-1)(6x-1)=0
问题求什么?再问:求x加y的值再答:x^2-2x+1+y^2-6y+9=0(x-1)^2+(y-3)^2=0x=1y=32x+3y=11
若多项式2乘x的平方加3乘x加7等于10则多项式6x的平方加9x减7等于几?2x²+3x+7=106x²+9x+21=306x²+9x=7∴6x²+9x-7=7
2x²-3x+6=0∵a=2,b=-3,c=6b²-4ac=(-3)²-4×2×6=9-48=-39<0∴原方程无实数根.
x²+2x-2=0x²+2x+1=2+1(x+1)²=3x+1=±√3x=±√3-1x1=√3-1x2=-√3-1