Question

решите систему уравнений {x2-xy=19 x-y=7​

Answer 1

Ответ:

Объяснение:

x²-xy=19

x-y=7

x(x-y)=19

x-y=7

x*7=19

y=x-7

x=19/7

y=19/7-7=(19-49)/7=-30/7

x=19/7 ; y=-30/7

Проверка

(19/7)²-(19/7)(-30/7)=(19*19+30*19)/49=19(19+30)/49=19*49/49=19

(19/7)-(-30/7)=(19/7)+(30/7)=49/7=7