`a) 4x(x - 5) - (x - 1)(4x - 3) = 5`
`<=> 4x^2 - 20x - (4x^2 - 3x - 4x + 3) = 5`
`<=> 4x^2 - 20x - 4x^2 + 3x + 4x - 3 = 5`
`<=> -13x - 3 = 5`
`<=> -13x = 8`
`<=> x = 8/(-13)`
Vậy `x = 8/(-13)`
`b) (3x - 4)(x - 2) = 3x(x - 9) - 3`
`<=> 3x^2 - 4x - 6x + 8 = 3x^2 - 27x - 3`
`<=> 3x^2 - 10x + 8 - 3x^2 + 27x + 3 = 0`
`<=> 17x + 11 = 0`
`<=> 17x = -11`
`<=> x = (-11)/17`
Vậy `x = (-11)/17`
`c) (x - 5)(x - 4) - (x + 1)(x - 2) = 7`
`<=> x^2 - 4x - 5x + 20 - (x^2 + x - 2x - 2) = 7`
`<=> x^2 - 9x + 20 - x^2 - x + 2x + 2 = 7`
`<=> -8x + 22 = 7`
`<=> -8x = -15`
`<=> x = 15/8`
Vậy `x = 15/8`
`d) 5x(x - 3) = (x - 2)(5x - 1) - 5`
`<=> 5x^2 - 15x = 5x^2 - 10x - x + 2 - 5`
`<=> 5x^2 - 15x - 5x^2 + 11x = -3`
`<=> -4x = -3`
`<=> x = 3/4`
Vậy `x = 3/4`