Question

Помогите пожалуйста :)
Задание во вложениях

Answer 1

$left { {{x^2-5xy+y^2=-47} atop {xy=21}} right. \ left { {{x^2-5cdot21+y^2=-47} atop {xy=21}} right. \ left { {{x^2+y^2=58} atop {xy=21}} right. \ x= frac{21}{y} \ (frac{21}{y} )^2+y^2=58 \ frac{441}{y^2} +y^2=58 \ 441+y^4=78y^2 \ a^2-58a+441=0 \ D_1=841-441=400 \ a_1=49 \ a_2=9$
$\ y^2=49 \ y_1=7 \ y_2=-7 \ y^2=9 \ y_3=3 \ y_4=-3 \ x_1= frac{21}{7}=3 \ x_2= frac{21}{-7}=-3 \ x_3= frac{21}{3}=7 \ x_4= frac{21}{3}=-7$
$|x+y|+|x-y|=|3+7|+|3-7|=10+4=14 \ |x+y|+|x-y|=|-3-7|+|-3+7|=10+4=14 \ |x+y|+|x-y|=|7+3|+|7-3|=10+4=14 \ |x+y|+|x-y|=|-7-3|+-7+3|=10+4=14$
Ответ: 14