2х / 3 = 0 или 4у/5=02х=0*3 4у=0*5х=0 у=03х/2=-4 или у=-43х=-4* -2=8х=8/3= 2,5
Ответы на вычисление:
1) -58
2) 5
3) 1/9
D = 4 - 4q.
x_1 =
![x_2 = \frac{-2 - \sqrt{4 - 4q} }{2} = \frac{-2 - 2\sqrt{1 - q} }{2} = -1 - \sqrt{1-q}](https://tex.z-dn.net/?f=x_2+%3D++%5Cfrac%7B-2+-++%5Csqrt%7B4+-+4q%7D+%7D%7B2%7D+%3D++%5Cfrac%7B-2+-++2%5Csqrt%7B1+-+q%7D+%7D%7B2%7D+%3D+-1+-++%5Csqrt%7B1-q%7D)
![x_2 - x_1 = -1 - \sqrt{1-q} - (-1 + \sqrt{1 - q} ) = -2 \sqrt{1 - q}](https://tex.z-dn.net/?f=x_2+-+x_1+%3D+-1+-+%5Csqrt%7B1-q%7D+-+%28-1+%2B+%5Csqrt%7B1+-+q%7D+%29+%3D+-2+%5Csqrt%7B1+-+q%7D+)
, т.е.
![x_2 - x_1 = -\sqrt{D}](https://tex.z-dn.net/?f=x_2+-+x_1+%3D+-%5Csqrt%7BD%7D+)
По обратной теореме Виета:
x₁ + x₂ = -2
x₂² - x₁² = (x₂ - x1)(x₁ + x₂)
![(-2 \sqrt{1-q} )*(-2) = 12](https://tex.z-dn.net/?f=%28-2+%5Csqrt%7B1-q%7D+%29%2A%28-2%29+%3D+12)
![\sqrt{1-q} =3](https://tex.z-dn.net/?f=+%5Csqrt%7B1-q%7D+%3D3)
![1-q = 9](https://tex.z-dn.net/?f=1-q+%3D+9)
![q = -8.](https://tex.z-dn.net/?f=q+%3D+-8.)
<span>Log3 x > log3 8
3 > 1
x > 8
Ответ: (8;+∞)
</span><span>
log1/3 x > log 1/3 5
1/3 < 1
x < 5
Ответ: (-∞; 5)
</span>
(3a - b)(a + b) + (b - 3a)(b + 3a) = (3a - b)(a + b) - (3a - b)(b + 3a) =
= (3a - b)(a + b - b - 3a) = - 2a(3a - b)