Tìm x bt (2x+3)(x+4)+(x-5)(x-2)=(3x-5)(x-4)

`(2x + 3)(x + 4) + (x - 5)(x-2) = (3x - 5)(x - 4)`

`  (2x^2 + 8x + 3x + 12) + (x^2 - 2x - 5x + 10) = 3x^2 - 12x - 5x + 20`

`  (2x^2 + 11x + 12) + (x^2 - 7x + 10) = 3x^2 - 17x + 20` 

`(2x^2 + x^2) + (11x - 4x) + (12 + 10) = 3x^2 - 17x + 20` 

`3x^2  + 4x + 22 = 3x^2 - 17x + 20`

`3x^2 + 4x + 22 - 3x^2 + 17x - 20 = 0`

`(3x^2-3x^2) + (17x + 4x) +  (22 - 20 ) = 0`

`21x + 2 = 0`

`21x = -2`

`x = (-2)/21`

Vậy `x = (-2)/21`