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受欢迎的代数 >

25t-0.05t^2=15t+200

解答

25 t - 0.05 t^{2} = 15 t + 200

解答

t = 20 (5 - 15), t = 20 (5 + 15)

+1

十进制

t = 22.54033 \dots, t = 177.45966 \dots

求解步骤

25 t - 0.05 t^{2} = 15 t + 200

在两边乘以

100

2500 t - 5 t^{2} = 1500 t + 20000

将

20000

para o lado esquerdo

2500 t - 5 t^{2} - 20000 = 1500 t

将

1500 t

para o lado esquerdo

- 5 t^{2} + 1000 t - 20000 = 0

使用求根公式求解

t_{1, 2} = \frac{- 1000 \pm 100 0 ^{2} - 4 ( - 5 ) ( - 20000 )}{2 ( - 5 )}

100 0^{2} - 4 (- 5) (- 20000) = 20015

t_{1, 2} = \frac{- 1000 \pm 200 15}{2 ( - 5 )}

将解分隔开

t_{1} = \frac{- 1000 + 200 15}{2 ( - 5 )}, t_{2} = \frac{- 1000 - 200 15}{2 ( - 5 )}

t = \frac{- 1000 + 200 15}{2 ( - 5 )} : 20 (5 - 15)

t = \frac{- 1000 - 200 15}{2 ( - 5 )} : 20 (5 + 15)

二次方程组的解是:

t = 20 (5 - 15), t = 20 (5 + 15)

作图

流行的例子

x^2+1 2/3 x-2/3 =0

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solvefor x,xy^2-2x^2y=4

so l v e f or x, x y^{2} - 2 x^{2} y = 4