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受欢迎的代数 >

completesquare x^2-8x-38=0

解答

x^{2} - 8 x - 38 = 0

解答

x = 36 + 4, x = - 36 + 4

+1

十进制

x = 11.34846 \dots, x = - 3.34846 \dots

求解步骤

x^{2} - 8 x - 38 = 0

将

38

到右边

x^{2} - 8 x = 38

改写为形式

(x + a)^{2} = b

(x - 4)^{2} = 54

若

f^{2} (x) = a

，解为

f (x) = a, - a

解

x - 4 = 54 : x = 36 + 4

解

x - 4 = - 54 : x = - 36 + 4

二次方程组的解是:

x = 36 + 4, x = - 36 + 4

作图

流行的例子

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