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受欢迎的代数 >

solvefor x,15(2x^2-y^2)=7xy

解答

求解

x, 15 (2 x^{2} - y^{2}) = 7 x y

解答

x = \frac{5 y}{6}, x = - \frac{3 y}{5}

求解步骤

15 (2 x^{2} - y^{2}) = 7 x y

展开

15 (2 x^{2} - y^{2}) : 30 x^{2} - 15 y^{2}

30 x^{2} - 15 y^{2} = 7 x y

将

7 x y

para o lado esquerdo

30 x^{2} - 15 y^{2} - 7 x y = 0

改写成标准形式

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

30 x^{2} - 7 y x - 15 y^{2} = 0

使用求根公式求解

x_{1, 2} = \frac{- ( - 7 y ) \pm ( - 7 y ) ^{2} - 4 \cdot 30 ( - 15 y ^{2} )}{2 \cdot 30}

化简

(- 7 y)^{2} - 4 \cdot 30 (- 15 y^{2}) : 43 y

x_{1, 2} = \frac{- ( - 7 y ) \pm 43 y}{2 \cdot 30}

将解分隔开

x_{1} = \frac{- ( - 7 y ) + 43 y}{2 \cdot 30}, x_{2} = \frac{- ( - 7 y ) - 43 y}{2 \cdot 30}

x = \frac{- ( - 7 y ) + 43 y}{2 \cdot 30} : \frac{5 y}{6}

x = \frac{- ( - 7 y ) - 43 y}{2 \cdot 30} : - \frac{3 y}{5}

二次方程组的解是:

x = \frac{5 y}{6}, x = - \frac{3 y}{5}

作图

流行的例子

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