1a) 2 + 6x > 9x - 5
6x - 9x > - 5 - 2
- 3x > - 7
![x<2\frac{1}{3} x<2\frac{1}{3}](https://tex.z-dn.net/?f=x%3C2%5Cfrac%7B1%7D%7B3%7D)
x ∈ (- ∞ ; 2 1/3)
1б)
![\frac{5+2x}{3}*9- \frac{x}{9} *9\leq1*9\\\\3(5+2x)-x\leq9\\15+6x-x\leq 9\\5x\leq-6\\x\leq-1,2 \frac{5+2x}{3}*9- \frac{x}{9} *9\leq1*9\\\\3(5+2x)-x\leq9\\15+6x-x\leq 9\\5x\leq-6\\x\leq-1,2](https://tex.z-dn.net/?f=%5Cfrac%7B5%2B2x%7D%7B3%7D%2A9-%20%5Cfrac%7Bx%7D%7B9%7D%20%2A9%5Cleq1%2A9%5C%5C%5C%5C3%285%2B2x%29-x%5Cleq9%5C%5C15%2B6x-x%5Cleq%209%5C%5C5x%5Cleq-6%5C%5Cx%5Cleq-1%2C2)
x ∈ (- ∞ , - 1,2]
2) (a + 5)(a - 2) > (a - 5)(a + 8)
a² - 2a + 5a - 10 > a² + 8a - 5a - 40
a² + 3a - 10 > a² + 3a - 40
- 10 > - 40 - верно при любых a
5) |1 - 2x| = 43
1 - 2x = 43 или 1 - 2x = - 43
- 2x = 43 - 1 - 2x = - 43 - 1
- 2x = 42 - 2x = - 44
x = - 21 x = 22
Ответ : - 21 ; 22