5y - ( 7 - 2y) - (7y + 8) = 2y
5y - 7 + 2y - 7y - 8 = 2y
(5y + 2y - 7y) - (7 + 8) = 2y
- 15 = 2y
2y = - 15
y = - 15/2
y = - 7,5
6у(13у-9) - 13у(6у - 1) = 24 +13
78у² - 54у - 78у² + 13у = 37
(78у² - 78у² ) - (54у-13у) = 37
-41у = 37
у= - ³⁷/₄₁
(2х - 3)² - (2х + 1)(2х - 5) = 3х - 14
(2х)² - 2*2х * 3 + 3² - (4х² - 10х + 2х - 5) = 3х - 14
4х² - 12х + 9 - (4х² - 8х - 5) = 3х - 14
4х² - 12х + 9 - 4х² + 8х + 5 = 3х - 14
(4х² - 4х²) - (12х - 8х) + (9 + 5) = 3х - 14
- 4х + 14 = 3х - 14
- 4х - 3х = - 14 - 14
- 7х = - 28
7х = 28
х = 28 : 7
х = 4