Ответ:

(3y - 1) × (5 - 2y) + ( 4 - 3y) × ( 5 + 2y) = 15

15y - 6y² - 5 + 2y + 20 + 8y - 15y - 6y²= 15

- 12y² + 10y + 15 = 15

-12y² + 10y + 15 - 15 = 0

-12y² + 10y = 0

- 2y ( 6y - 5) = 0

- 2y = 0 6y - 5 =0

-y = 0 6y = 5

y1 =0 y2 = 5/6