Question

{x^2+y=5 -> {y=5-x^2
{x-y=7 {y=x-7

Answer 1

Ответ:

(3; 4) ; (-4; -11)

Объяснение:

$y = 5 - {x}^{2} \\ x - (5 - {x}^{2} ) = 7 \\ \\ x - 5 + {x}^{2} = 7 \\ {x}^{2} + x - 5 - 7 = 0 \\ {x}^{2} + x - 12 = 0 \\ D = {1}^{2} - 4 \times 1 \times ( - 12) = 1 +48 = 49 \\ \sqrt{D} = \sqrt{49} = 7 \\ x_{1} = \frac{ - 1 + 7}{2} = \frac{6}{2} = 3 \\ x_{2} = \frac{ - 1 - 7}{2} = \frac{ - 8}{2} = - 4$

$x_{1} = 3 \\ y_{1} = - 4 \\ \\ x_{2} = - 4 \\ y_{2} = - 11$