Решите систему уравнений {(x-1) (y+10)=9 {х-у=11

Question

Решите систему уравнений {(x-1) (y+10)=9
{х-у=11

Answer 1

{(x-1)(y+10)=9. {x=11+y
{x-y=11. =>. { (11+y-1)(y+10)=9
(y+10)(y+10)=9
(y+10)^2=9
y+10=-/~9~
y+10=3. y+10=-3
y=-7. y=7
X=11+y. X=11+(-7)=4. X=11+7=18
Ответ:
(4;-7); (18;7)