Решите уравнение:

2

Упростить выражение:

при x = 11

2x^2+3x = 2x^2+21

3x = 21

x = 7

(3x+1) (4x-5) = 12x^2-13x+1

12x^2-11x-5 = 12x^2-13x+1

2x = 6

x = 3

(2x-3) (3x+7) - (x-5) = 12x^2-13x+1

6x^2+14x-9x-21-x+5 = 12x^2-13x+1

-6x^2+17x = 17

x (17-6x) = 17