Question

[Nguyễn Quang Duy Anh 28/08/2011]

- 12(11 - 18) - (x + 1) ^ 2 = 59

Answer 1

[『Kuroba ム Tsuki Ryoo ︵²ᵏ⁷』]

`#040911`

`-12(11 - 18) - (x + 1)^2 = 59`

`\Rightarrow -12. (-7) - (x + 1)^2 = 59`

`\Rightarrow 84 - (x + 1)^2 = 59`

`\Rightarrow (x + 1)^2 = 84 - 59`

`\Rightarrow (x + 1)^2 =25`

`\Rightarrow (x + 1)^2 =`\(\left(\pm5\right)^2\)

\(\Rightarrow\left[{}\begin{matrix}x+1=5\\x+1=-5\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=5-1\\x=-5-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=4\\x=-6\end{matrix}\right.\)

Vậy, `x \in`\(\left\{-6;4\right\}.\)