Первая система под 4 номером
(√(x-1)+√(y+1))²=9 x-1+2√(xy+x-y-1)+y+1=9 2√(xy+x-y-1)=9-x-y xy=5-x+y 2√(5-x+y+x-y-1)=9-x-y 2√4=9-x-y 2*2=9-x-y x=9-4-y x=5-y y(5-y)=5-(5-y)+y 5y-y²=5-5+y+y y²-3y=0 y(y-3)=0 y1=0⇒x1=5 y2=3⇒x2=2 Ответ (5;0);(2;3)