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受欢迎的代数 >

solvefor x,x^2+mx+7=0

解答

x, x^{2} + m x + 7 = 0

解答

x = \frac{- m + m ^{2} - 28}{2}, x = \frac{- m - m ^{2} - 28}{2}

求解步骤

x^{2} + m x + 7 = 0

使用求根公式求解

x_{1, 2} = \frac{- m \pm m ^{2} - 4 \cdot 1 \cdot 7}{2 \cdot 1}

化简

m^{2} - 4 \cdot 1 \cdot 7 : m^{2} - 28

x_{1, 2} = \frac{- m \pm m ^{2} - 28}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- m + m ^{2} - 28}{2 \cdot 1}, x_{2} = \frac{- m - m ^{2} - 28}{2 \cdot 1}

x = \frac{- m + m ^{2} - 28}{2 \cdot 1} : \frac{- m + m ^{2} - 28}{2}

x = \frac{- m - m ^{2} - 28}{2 \cdot 1} : \frac{- m - m ^{2} - 28}{2}

二次方程组的解是:

x = \frac{- m + m ^{2} - 28}{2}, x = \frac{- m - m ^{2} - 28}{2}

作图

流行的例子

5 b^{2} + 4 b + 4 = 0

\frac{1}{16} x^{2} + x + 4 = 0

completesquare x^2+28x

co m pl e t es q u a re x^{2} + 28 x

1+4+7+10(3n-2)=(n(3n-1))/2

1 + 4 + 7 + 10 (3 n - 2) = \frac{n ( 3 n - 1 )}{2}

2 x (1 + x) = 4