Question

Решение систем уравнений второй степени

Answer 1

$left { {{y+x=-4} atop {yx+7y=-4}} right. ; left { {{x=-4-y} atop {y(-4-y)+7y=-4}} right. ; left { {{x=-4-y} atop {-4y-y^2+7y+4=0}} right. ; left { {{x=-4-y} atop {y^2-3y-4=0}} right. \\y^2-3y-4=0; ,; ; y_1=-1,; y_2=4; (teorema; Vieta)\\ left { {{x_1=-3} atop {y_1=-1}} right. ; left { {{x_2=-8} atop {y_2=4}} right.$