8x^2+26x+21=0

解答

8 x^{2} + 26 x + 21 = 0

x = - \frac{3}{2}, x = - \frac{7}{4}

十进制

x = - 1.5, x = - 1.75

求解步骤

8 x^{2} + 26 x + 21 = 0

使用求根公式求解

x_{1, 2} = \frac{- 26 \pm 2 6 ^{2} - 4 \cdot 8 \cdot 21}{2 \cdot 8}

2 6^{2} - 4 \cdot 8 \cdot 21 = 2

x_{1, 2} = \frac{- 26 \pm 2}{2 \cdot 8}

将解分隔开

x_{1} = \frac{- 26 + 2}{2 \cdot 8}, x_{2} = \frac{- 26 - 2}{2 \cdot 8}

x = \frac{- 26 + 2}{2 \cdot 8} : - \frac{3}{2}

x = \frac{- 26 - 2}{2 \cdot 8} : - \frac{7}{4}

二次方程组的解是:

x = - \frac{3}{2}, x = - \frac{7}{4}

f a c t or 125 q^{6} - r^{6} s^{3}

f a c t or 36 x y^{5} m - 6 x y^{4} m^{6} + 42 x y^{3} m^{4}

s im pl i f y \frac{1}{4} - \frac{1}{6} - \frac{1}{9} + \frac{1}{26}

2 (3 x - 4) = 22

f a c t or 25 x^{2} - 64 y^{2}