{x^2+y^2=26 => (x+y)^2-2xy=26
{xy-5=0
{(x+y)^2-2xy=26
{xy=5
{(x+y)^2-10=26
{ (x+y)^2=36
{x+y=6
{y=6-x
{6x-x^2=5
{x^2-6x+5=0
D=36-4*1*5=V16 =4
x=6+4/2=5
x2=6-4/2=1
y=1
y=5
{x^2+y^2=26 => (x+y)^2-2xy=26
{xy-5=0
{(x+y)^2-2xy=26
{xy=5
{(x+y)^2-10=26
{xy=5
{ (x+y)^2=36
{xy=5
{x+y=6
{xy=5
{y=6-x
{6x-x^2=5
{x^2-6x+5=0
D=36-4*1*5=V16 =4
x=6+4/2=5
x2=6-4/2=1
y=1
y=5