quadraticformula (x-2)(x+10)=13

解答

(x - 2) (x + 10) = 13

x = 3, x = - 11

求解步骤

(x - 2) (x + 10) = 13

展开

(x - 2) (x + 10) : x^{2} + 8 x - 20

x^{2} + 8 x - 20 = 13

将

13

para o lado esquerdo

x^{2} + 8 x - 33 = 0

使用求根公式求解

x_{1, 2} = \frac{- 8 \pm 8 ^{2} - 4 \cdot 1 \cdot ( - 33 )}{2 \cdot 1}

8^{2} - 4 \cdot 1 \cdot (- 33) = 14

x_{1, 2} = \frac{- 8 \pm 14}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- 8 + 14}{2 \cdot 1}, x_{2} = \frac{- 8 - 14}{2 \cdot 1}

x = \frac{- 8 + 14}{2 \cdot 1} : 3

x = \frac{- 8 - 14}{2 \cdot 1} : - 11

二次方程组的解是:

x = 3, x = - 11

q u a d r a t i c f or m u l a x (x - 8) = 0

so l v e f or x, 25 6^{x} = 64

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

so l v e f or R, R = \frac{( \frac{200}{3} )}{1.5} \cdot \frac{12000}{3}

so l v e f or r, - 10 - 5 r + 7 r = 10 - 8 (- 4 r - 5)