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受欢迎的代数 >

4x^2=4(x+2)

解答

4 x^{2} = 4 (x + 2)

解答

x = 2, x = - 1

求解步骤

4 x^{2} = 4 (x + 2)

展开

4 (x + 2) : 4 x + 8

4 x^{2} = 4 x + 8

将

8

para o lado esquerdo

4 x^{2} - 8 = 4 x

将

4 x

para o lado esquerdo

4 x^{2} - 8 - 4 x = 0

改写成标准形式

a x^{2} + b x + c = 0

4 x^{2} - 4 x - 8 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 4 ) \pm ( - 4 ) ^{2} - 4 \cdot 4 ( - 8 )}{2 \cdot 4}

(- 4)^{2} - 4 \cdot 4 (- 8) = 12

x_{1, 2} = \frac{- ( - 4 ) \pm 12}{2 \cdot 4}

将解分隔开

x_{1} = \frac{- ( - 4 ) + 12}{2 \cdot 4}, x_{2} = \frac{- ( - 4 ) - 12}{2 \cdot 4}

x = \frac{- ( - 4 ) + 12}{2 \cdot 4} : 2

x = \frac{- ( - 4 ) - 12}{2 \cdot 4} : - 1

二次方程组的解是:

x = 2, x = - 1

作图

流行的例子

solvefor x,x^2-x-12=0

so l v e f or x, x^{2} - x - 12 = 0

solvefor z,x^2+y^2+z^2=1

so l v e f or z, x^{2} + y^{2} + z^{2} = 1

(5 x - 1)^{2} - 1 = 15

3 x^{2} - 48 = - 6 x

1 = 2 x^{2} - 2