一道简单数学题，一元二次方程，2x的平方-5x-3=0,用配方法！很简单，但我忘了配方法！
2x\u7684\u5e73\u65b9+3=5x -3x\u7684\u5e73\u65b9-2x+1=0 \u8c01\u80fd\u7528\u914d\u65b9\u6cd5\u89e3\u51b3\u4e00\u4e0b\u8fd9\u4e24\u4e2a\u4e00\u5143\u4e8c\u6b21\u65b9\u7a0b\uff0c\u6211\u5f88\u6025\u7684\uff0c\u62dc\u6258\u4e86\uff012x\u7684\u5e73\u65b9+3=5x
2x²-5x=-3
x²-5x/2+25/16=-3/2+25/16
(x-5/4)²=1/16
x-5/4=1/4 x-5/4=-1/4
x=3/2 x=1
-3x\u7684\u5e73\u65b9-2x+1=0
x²+2x/3+1/9=1/3+1/9
(x+1/3)²=4/9
x+1/3=2/3 x+1/3=-2/3
x=1/3 x=-1
\uff081\uff09X²-7X=1
X²-7X+49/4=1+49/4
\uff08X-7/2\uff09²=53/4
X-7/2=\u00b1\u221a53/2
X=\u00b1\u221a53/2+7/2
X1=\u221a53/2+7/2\uff0cX2=-\u221a53/2+7/2
\uff082\uff09X²-2X+1=25
\uff08X-1\uff09²=25
X-1=\u00b15
X=\u00b15+1
X1=5+1=6\uff0cX2=-5+1=-4
\uff083\uff09X²+2X+7=11
X²+2X+1=5
\uff08X+1\uff09²=5
X+1=\u00b1\u221a5
X=\u00b1\u221a5-1
X1=\u221a5-1\uff0cX2=-\u221a5-1
\uff084\uff09X²-5X-10=0
X²-5X=10
X²-5X+25/4=10+25/4
\uff08X-5/2\uff09²=65/4
X-5/2=\u00b1\u221a65/2
X=\u00b1\u221a65/2+5/2
X1=\u221a65/2+5/2\uff0cX2=-\u221a65/2+5/2
2（X-四分之五）方=八分之四十九
（X-四分之五）方=十六分之四十九
X-四分之五=正负四分之七
X1=3，X2=-二分之一
2x的平方-5x-3=0
x^2-5/2*x=3/2
(x-5/4)^2=3/2+(5/4)^2
(x-5/4)^2=49/16
x-5/4=7/4或x-5/4=-7/4
x1=3
x2=-1/2
2(x-5)(x-3)=0
x1=-0.5
x2=3
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