Question

Решите систему уравнений х+3у=10 и ху=3

Answer 1

$x + 3y = 10 \\ xy = 3 \\ \\ x = 10 - 3y \\ \\ (10 - 3y)y = 3 \\ 10y - 3 {y}^{2} - 3 = 0 \\ 3 {y}^{2} - 10y + 3 = 0 \\ \\d = 100 - 36 = 64 = {8}^{2} \\ y = \frac{10 + - 8}{6} \\ \\ y = \frac{18}{6} = 3 \\ x = 1 \\ \\ y = \frac{2}{6} = \frac{1}{3} \\ x = 9$
Ответ: (1;3) или (9;1/3)