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受欢迎的代数 >

(80-2x)(1200+200x)-1600x-6400=122000

解答

(80 - 2 x) (1200 + 200 x) - 1600 x - 6400 = 122000

解答

x = 3, x = 27

求解步骤

(80 - 2 x) (1200 + 200 x) - 1600 x - 6400 = 122000

展开

(80 - 2 x) (1200 + 200 x) - 1600 x - 6400 : - 400 x^{2} + 12000 x + 89600

- 400 x^{2} + 12000 x + 89600 = 122000

将

122000

para o lado esquerdo

- 400 x^{2} + 12000 x - 32400 = 0

使用求根公式求解

x_{1, 2} = \frac{- 12000 \pm 1200 0 ^{2} - 4 ( - 400 ) ( - 32400 )}{2 ( - 400 )}

1200 0^{2} - 4 (- 400) (- 32400) = 9600

x_{1, 2} = \frac{- 12000 \pm 9600}{2 ( - 400 )}

将解分隔开

x_{1} = \frac{- 12000 + 9600}{2 ( - 400 )}, x_{2} = \frac{- 12000 - 9600}{2 ( - 400 )}

x = \frac{- 12000 + 9600}{2 ( - 400 )} : 3

x = \frac{- 12000 - 9600}{2 ( - 400 )} : 27

二次方程组的解是:

x = 3, x = 27

作图

流行的例子

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(11 x - 18) (6 x + 10) = 0

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solvefor y,x=y^2-4y+3

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