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受欢迎的代数 >

2+6t-4.9t^2=0

解答

2 + 6 t - 4.9 t^{2} = 0

解答

t = - \frac{2 ( 470 - 15 )}{49}, t = \frac{2 ( 15 + 470 )}{49}

+1

十进制

t = - 0.27263 \dots, t = 1.49712 \dots

求解步骤

2 + 6 t - 4.9 t^{2} = 0

在两边乘以

10

20 + 60 t - 49 t^{2} = 0

改写成标准形式

a x^{2} + b x + c = 0

- 49 t^{2} + 60 t + 20 = 0

使用求根公式求解

t_{1, 2} = \frac{- 60 \pm 6 0 ^{2} - 4 ( - 49 ) \cdot 20}{2 ( - 49 )}

6 0^{2} - 4 (- 49) \cdot 20 = 4470

t_{1, 2} = \frac{- 60 \pm 4 470}{2 ( - 49 )}

将解分隔开

t_{1} = \frac{- 60 + 4 470}{2 ( - 49 )}, t_{2} = \frac{- 60 - 4 470}{2 ( - 49 )}

t = \frac{- 60 + 4 470}{2 ( - 49 )} : - \frac{2 ( 470 - 15 )}{49}

t = \frac{- 60 - 4 470}{2 ( - 49 )} : \frac{2 ( 15 + 470 )}{49}

二次方程组的解是:

t = - \frac{2 ( 470 - 15 )}{49}, t = \frac{2 ( 15 + 470 )}{49}

作图

流行的例子

(s + 3) (s + 5) = 0

(5x+2)(5x-2)=(A+B)(A-B)

(5 x + 2) (5 x - 2) = (A + B) (A - B)

(x + 2)^{2} = 8 + x

completesquare x^2-5x+10

co m pl e t es q u a re x^{2} - 5 x + 10

(2 x - 5)^{2} = 7