quadraticformula 2x^2-7x-3=0

解答

2 x^{2} - 7 x - 3 = 0

x = \frac{7 + 73}{4}, x = \frac{7 - 73}{4}

十进制

x = 3.88600 \dots, x = - 0.38600 \dots

求解步骤

2 x^{2} - 7 x - 3 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 7 ) \pm ( - 7 ) ^{2} - 4 \cdot 2 ( - 3 )}{2 \cdot 2}

(- 7)^{2} - 4 \cdot 2 (- 3) = 73

x_{1, 2} = \frac{- ( - 7 ) \pm 73}{2 \cdot 2}

将解分隔开

x_{1} = \frac{- ( - 7 ) + 73}{2 \cdot 2}, x_{2} = \frac{- ( - 7 ) - 73}{2 \cdot 2}

x = \frac{- ( - 7 ) + 73}{2 \cdot 2} : \frac{7 + 73}{4}

x = \frac{- ( - 7 ) - 73}{2 \cdot 2} : \frac{7 - 73}{4}

二次方程组的解是:

x = \frac{7 + 73}{4}, x = \frac{7 - 73}{4}

65% o f 80

q u a d r a t i c f or m u l a x^{2} - 10 x = - 25

so l v e f or x, 3^{x} = 13

e x p an d sin (4 x)

so l v e f or d, - 9 d - 4 d - 9 d + 9 = - 13