-х-2+3х-9 = 12-3х-3
2х - 11 = 9 - 3х
2х +3х = 9+11
5х = 20
х = 20\5
х = 4
y = - x² - 2x + 1 y = - x - 1
- x² - 2x + 1 = - x - 1
- x² - 2x + 1 + x + 1 = 0
- x² - x + 2 = 0
x² + x - 2 = 0
D = 1² - 4 * (- 2) = 1 +8 = 9 = 3²
![x_{1}= \frac{-1+3}{2}=1\\x_{2} =\frac{-1-3}{2}=-2\\y_{1}=-1-1=-2\\y_{2}=-(-2)-1=2-1=1](https://tex.z-dn.net/?f=x_%7B1%7D%3D+%5Cfrac%7B-1%2B3%7D%7B2%7D%3D1%5C%5Cx_%7B2%7D+%3D%5Cfrac%7B-1-3%7D%7B2%7D%3D-2%5C%5Cy_%7B1%7D%3D-1-1%3D-2%5C%5Cy_%7B2%7D%3D-%28-2%29-1%3D2-1%3D1)
Ответ : (1 ; - 2) , ( - 2 ; 1)
X^2+9x+20>0
Решим уравнение
х²+9х+20=0
х=-4 и х=-5
Наносим на числовую ось:
У=(х+2)(х-8).
у=х^2-8х+2х-16.
у=х^2-6х-16