Question

ОЧЕНЬ СРОЧНО РАСПИШИТЕ ЧТОБ БЫЛО ПОНЯТНО ПЖПДП

Answer 1

$1) \: \frac{3x}{x - 4} - \frac{x + 8}{x - 4} = \frac{3x - x + 8}{x - 4} = \frac{2x + 8}{x - 4} = \frac{2(x + 4)}{x - 4} = \frac{ - 2(x - 4)}{x - 4} = - 2 \\ 2) \: \frac{y - x}{ {y}^{2} - 9 } - \frac{x - 3}{9 - {y}^{2} } = \frac{y - x}{ {y}^{2} - 9 } + \frac{x - 3}{ {y}^{2} - 9} = \frac{y - x + x - 3}{ {y}^{2} - 9} = \frac{y - 3}{ {y}^{2} - 9} = \frac{1}{y + 3} \\ 3) \: \frac{4x}{x + 1} - \frac{x - 3}{x + 1} = \frac{4x - x - 3}{x + 1} = \frac{3x - 3}{x + 1} \\ 4) \: \frac{2 - x}{4 - {y}^{2} } - \frac{x + y}{ {y}^{2} - 4 } = \frac{2 - x}{4 - {y}^{2} } + \frac{x + y}{4 - {y}^{2} } = \frac{2 - x + x + y}{4 - {y}^{2} } = \frac{2 + y}{4 - {y}^{2} } = \frac{1}{2 + y}$