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受欢迎的代数 >

7v^2-14v+4=3

解答

7 v^{2} - 14 v + 4 = 3

解答

v = \frac{7 + 42}{7}, v = \frac{7 - 42}{7}

+1

十进制

v = 1.92582 \dots, v = 0.07417 \dots

求解步骤

7 v^{2} - 14 v + 4 = 3

将

3

para o lado esquerdo

7 v^{2} - 14 v + 1 = 0

使用求根公式求解

v_{1, 2} = \frac{- ( - 14 ) \pm ( - 14 ) ^{2} - 4 \cdot 7 \cdot 1}{2 \cdot 7}

(- 14)^{2} - 4 \cdot 7 \cdot 1 = 242

v_{1, 2} = \frac{- ( - 14 ) \pm 2 42}{2 \cdot 7}

将解分隔开

v_{1} = \frac{- ( - 14 ) + 2 42}{2 \cdot 7}, v_{2} = \frac{- ( - 14 ) - 2 42}{2 \cdot 7}

v = \frac{- ( - 14 ) + 2 42}{2 \cdot 7} : \frac{7 + 42}{7}

v = \frac{- ( - 14 ) - 2 42}{2 \cdot 7} : \frac{7 - 42}{7}

二次方程组的解是:

v = \frac{7 + 42}{7}, v = \frac{7 - 42}{7}

作图

流行的例子

9 x^{2} + 30 x + 28 = 0

3 x^{2} + 15 x = 72

x^{2} - 18 x + 79 = 0

(x - 2) (x - 9) = 0

- 3 x^{2} + x = 0