Решите систему:
1\x+1\y=5\4
xy=4

1/x+1/y=5/44(y+x)=5xy4(y+x)=20y+x=5x=5-yy(5-y)=4y²-5y+4=0y1+y2=5 U y1*y2=4y1=1⇒x1=5-1=4y2=4⇒x2=5-4=1Ответ (4;1);(1;4)