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)