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信息发布者:
$x(x + 2)=224$
$39.75(1 + x)^{2}=44.50$
$x^{2}+(x + 7)^{2}=13^{2}$
$x\times1=(1 - x)^{2}$
解:​$x^2=100$​
​$ x = \pm \sqrt {100}$​
​$ x_{1}=10,$​​$x_{2}=-10$​
解:​$9x^2=1$​
​$x^2=\frac {1}{9}$​
​$ x=\pm \frac {1}{3}$​
​$x_{1}=\frac {1}{3},$​​$x_{2}=-\frac {1}{3}$​
解:​$2x^2-32 = 0$​
​$ x^2=16$​
​$ x = \pm \sqrt {16}$​
​$ x_{1}=4,$​​$x_{2}=-4$​
解:​$9y^2-1 = 3$​
​$ y^2=\frac {4}{9}$​
​$ y = \pm \sqrt {\frac {4}{9}}$​
​$y_{1}=\frac {2}{3},$​​$y_{2}=-\frac {2}{3}$​
解:​$(x + 1)(x - 1)=8$​
​$ x^2-1 = 8$​
​$ x^2=9$​
​$ x = \pm \sqrt {9}$​
​$ x_{1}=3,$​​$x_{2}=-3$​
解:​$4x(x - 2)=1 - 8x$​
​$ 4x^2-8x = 1 - 8x$​
​$ 4x^2=1$​
​$ x^2=\frac {1}{4}$​
​$ x = \pm \sqrt {\frac {1}{4}}$​
​$x_{1}=\frac {1}{2},$​​$x_{2}=-\frac {1}{2}$​