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受欢迎的代数 >

x^2+18x=15

解答

x^{2} + 18 x = 15

解答

x = - 9 + 46, x = - 9 - 46

+1

十进制

x = 0.79795 \dots, x = - 18.79795 \dots

求解步骤

x^{2} + 18 x = 15

将

15

para o lado esquerdo

x^{2} + 18 x - 15 = 0

使用求根公式求解

x_{1, 2} = \frac{- 18 \pm 1 8 ^{2} - 4 \cdot 1 \cdot ( - 15 )}{2 \cdot 1}

1 8^{2} - 4 \cdot 1 \cdot (- 15) = 86

x_{1, 2} = \frac{- 18 \pm 8 6}{2 \cdot 1}

将解分隔开

x_{1} = \frac{- 18 + 8 6}{2 \cdot 1}, x_{2} = \frac{- 18 - 8 6}{2 \cdot 1}

x = \frac{- 18 + 8 6}{2 \cdot 1} : - 9 + 46

x = \frac{- 18 - 8 6}{2 \cdot 1} : - 9 - 46

二次方程组的解是:

x = - 9 + 46, x = - 9 - 46

作图

流行的例子

d=0.006(1-(((1.82)-(d)(1500)))/(-3))^2

d = 0.006 (1 - \frac{( ( 1.82 ) - ( d ) ( 1500 ) )}{- 3})^{2}

0 = a (x - 3)^{2} + 1

completesquare 6x^2+5x-1

co m pl e t es q u a re 6 x^{2} + 5 x - 1

(x+2)^2+11(x+2)-12=0

(x + 2)^{2} + 11 (x + 2) - 12 = 0

solvefor y,y^2-2xy+9=0

so l v e f or y, y^{2} - 2 x y + 9 = 0