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受欢迎的代数 >

3x^2= 2/5 x+4/5+2x^2

解答

3 x^{2} = \frac{2}{5} x + \frac{4}{5} + 2 x^{2}

解答

x = - \frac{- 1 + 21}{5}, x = \frac{1 + 21}{5}

+1

十进制

x = - 0.71651 \dots, x = 1.11651 \dots

求解步骤

3 x^{2} = \frac{2}{5} x + \frac{4}{5} + 2 x^{2}

在两边乘以

5

15 x^{2} = 2 x + 4 + 10 x^{2}

交换两边

2 x + 4 + 10 x^{2} = 15 x^{2}

将

15 x^{2}

para o lado esquerdo

2 x + 4 - 5 x^{2} = 0

改写成标准形式

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

- 5 x^{2} + 2 x + 4 = 0

使用求根公式求解

x_{1, 2} = \frac{- 2 \pm 2 ^{2} - 4 ( - 5 ) \cdot 4}{2 ( - 5 )}

2^{2} - 4 (- 5) \cdot 4 = 221

x_{1, 2} = \frac{- 2 \pm 2 21}{2 ( - 5 )}

将解分隔开

x_{1} = \frac{- 2 + 2 21}{2 ( - 5 )}, x_{2} = \frac{- 2 - 2 21}{2 ( - 5 )}

x = \frac{- 2 + 2 21}{2 ( - 5 )} : - \frac{- 1 + 21}{5}

x = \frac{- 2 - 2 21}{2 ( - 5 )} : \frac{1 + 21}{5}

二次方程组的解是:

x = - \frac{- 1 + 21}{5}, x = \frac{1 + 21}{5}

作图

流行的例子

2 x^{2} - 4 = 10

5 v^{2} + 4 = - 9 v

solvefor x,f=(m-2)x^2+(n-1)x+(p-3)

so l v e f or x, f = (m - 2) x^{2} + (n - 1) x + (p - 3)

x^{2} + 10 x - 375 = 0

4 w^{2} + 8 w + 4 = 0