zs

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

受欢迎的代数 >

y^2-7.8y=-12.65

解答

y^{2} - 7.8 y = - 12.65

解答

y = \frac{11}{2}, y = \frac{23}{10}

+1

十进制

y = 5.5, y = 2.3

求解步骤

y^{2} - 7.8 y = - 12.65

在两边乘以

100

100 y^{2} - 780 y = - 1265

将

1265

para o lado esquerdo

100 y^{2} - 780 y + 1265 = 0

使用求根公式求解

y_{1, 2} = \frac{- ( - 780 ) \pm ( - 780 ) ^{2} - 4 \cdot 100 \cdot 1265}{2 \cdot 100}

(- 780)^{2} - 4 \cdot 100 \cdot 1265 = 320

y_{1, 2} = \frac{- ( - 780 ) \pm 320}{2 \cdot 100}

将解分隔开

y_{1} = \frac{- ( - 780 ) + 320}{2 \cdot 100}, y_{2} = \frac{- ( - 780 ) - 320}{2 \cdot 100}

y = \frac{- ( - 780 ) + 320}{2 \cdot 100} : \frac{11}{2}

y = \frac{- ( - 780 ) - 320}{2 \cdot 100} : \frac{23}{10}

二次方程组的解是:

y = \frac{11}{2}, y = \frac{23}{10}

作图

流行的例子

completesquare x^2-4x-10

co m pl e t es q u a re x^{2} - 4 x - 10

C=(2x-3)(2x-2)-2x(x-5)

C = (2 x - 3) (2 x - 2) - 2 x (x - 5)

25 x^{2} + 64 = 0

3 x (x - 1) = 5 - 3 x

solvefor a,f(a+1)=2(a+1)^2-3

so l v e f or a, f (a + 1) = 2 (a + 1)^{2} - 3