`(0,4x +1)/(x-1) = (2x-1)/(5x+3)`
`<=> (0,4x +1)(5x+3) = (x-1)(2x-1)`
`<=> 2/5x(5x+3) + 5x+3 = x(2x-1) -(2x-1)`
`<=> 2x^2 + 6/5x +5x+3 = 2x^2 - x -2x +1`
`<=> 2x^2 + 6/5x +5x -2x^2 +x +2x = 1-3`
`<=> 46/5x = -2`
`<=> x = -2 * 5/46 = -10/46 = -5/23`
Vậy `x=-5/23`