15х - 7х = 11х - 21
8x - 11x = - 21
- 3x = - 21
x = 7
1) 3 + 3 * (-1/3) = 3 - 1 = 2;
2) 3 + 3 * (-3) = 3 - 9 = -6;
3) 2 > -6 значит 3+3a при a = (-1/3) > 3+3a при a= -3;
6x<9x+15
6x-9x<15
-3x<15
x>-5
36t²-(t-p)² =
(6t-(t-p))(6t+(t-p)) =
(6t-t+p)(6t+t-p) =
(5t+p)(7t-p).
Ответ: (5t+p)(7t-p).