quadraticformula x^2-9x=10

解答

x^{2} - 9 x = 10

x = 10, x = - 1

求解步骤

x^{2} - 9 x = 10

将

10

para o lado esquerdo

x^{2} - 9 x - 10 = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 9 ) \pm ( - 9 ) ^{2} - 4 \cdot 1 \cdot ( - 10 )}{2 \cdot 1}

(- 9)^{2} - 4 \cdot 1 \cdot (- 10) = 11

x_{1, 2} = \frac{- ( - 9 ) \pm 11}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- ( - 9 ) + 11}{2 \cdot 1}, x_{2} = \frac{- ( - 9 ) - 11}{2 \cdot 1}

x = \frac{- ( - 9 ) + 11}{2 \cdot 1} : 10

x = \frac{- ( - 9 ) - 11}{2 \cdot 1} : - 1

二次方程组的解是:

x = 10, x = - 1

so l v e f or x, 5^{x} = 55

so l v e f or x, \frac{5}{( x - 5 )} = \frac{x}{( x - 5 )} - \frac{5}{4}

so l v e f or x, 1 - 2 x = 9

so l v e f or x, 4^{x} = 17

s im pl i f y (- 7) - (4)