Question

у меня контороха пж помогите ​

Answer 1

Объяснение:

$\frac{ {x}^{2} + 1 }{5} - \frac{x + 1}{4} = 1$

$4( {x}^{2} + 1) - 5(x + 1) = 1 \times 20$

$4 {x}^{2} + 4 - 5x - 5 = 20$

$4 {x}^{2} - 5x - 21 = 0$

$d = ( - 5)^{2} - 4 \times 4 \times ( - 21) = 361$

$x1 = \frac{5 - 19}{8} = - 1 \frac{3}{4}$

$x2 = \frac{5 + 19}{8} = 3$