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受欢迎的代数 >

3u^2=30u-9

解答

3 u^{2} = 30 u - 9

解答

u = 5 + 22, u = 5 - 22

+1

十进制

u = 9.69041 \dots, u = 0.30958 \dots

求解步骤

3 u^{2} = 30 u - 9

将

9

para o lado esquerdo

3 u^{2} + 9 = 30 u

将

30 u

para o lado esquerdo

3 u^{2} + 9 - 30 u = 0

改写成标准形式

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

3 u^{2} - 30 u + 9 = 0

使用求根公式求解

u_{1, 2} = \frac{- ( - 30 ) \pm ( - 30 ) ^{2} - 4 \cdot 3 \cdot 9}{2 \cdot 3}

(- 30)^{2} - 4 \cdot 3 \cdot 9 = 622

u_{1, 2} = \frac{- ( - 30 ) \pm 6 22}{2 \cdot 3}

将解分隔开

u_{1} = \frac{- ( - 30 ) + 6 22}{2 \cdot 3}, u_{2} = \frac{- ( - 30 ) - 6 22}{2 \cdot 3}

u = \frac{- ( - 30 ) + 6 22}{2 \cdot 3} : 5 + 22

u = \frac{- ( - 30 ) - 6 22}{2 \cdot 3} : 5 - 22

二次方程组的解是:

u = 5 + 22, u = 5 - 22

作图

流行的例子

g (8) = n^{2} + 3

7 x^{2} + 9 = 5 x^{2} - 2

m^{2} + 15 m + 56 = 0

5 (3 - 2 y) 4 y = 3

(x-5)^2+(x-5)=0

(x - 5)^{2} + (x - 5) = 0