Đáp án + Giải thích các bước giải
`B=(3x)/(x-1)-(2x)/(x+1)+(x-3)/(1-x^2)`
ĐKXĐ : `x \ne +-1; x \ne 3`
`B=[3x(x+1)]/[(x-1)(x+1)]-[2x(x-1)]/[(x+1)(x-1)]-(x-3)/[(x-1)(x+1)]`
`B=[3x(x+1)-2x(x-1)-(x-3)]/[(x-1)(x+1)]`
`B=(3x^(2)+3x-2x^(2)+2x-x+3)/[(x-1)(x+1)]`
`B=(x^(2)+4x+3)/[(x-1)(x+1)]`
`B=[(x+1)(x+3)]/[(x-1)(x+1)]`
`B=(x+3)/(x-1)`
`#Study well`