Question

{x2+y2=17 {xy=4 pojalusta bisto pomogite

Answer 1

{x²+y²=17
{xy=4

{(x+y)²-2xy=17
{xy=4

(x+y)²-8=17
(x+y)²=25
(x+y)=±5

1){x+y=5;x=5-y
{xy=4
(5-y)y=4
5y-y²=4
y²-5y+4=0
D=25-16=9=3²
y=(5±3)/2
y1=4;y2=1
x1=1;x2=4

2){x+y=-5;x=-5-y
{xy=4
(-5-y)y=4
y²+5y+4=0
y=(-5±3)/2
y1=-4;y2=-1
x1=-1;x2==-4

otvet (1;4);(4;1);(-1;-4);((-4;-1)