[tex]\left \{ {{x^{2}+y^{2} =41 } \atop {y + x = 9}} ight.[/tex]

I hope this helps you

подставить y во втором в первое.

x²+(9-x)² =41

x²+81-18x+x² =41

2x²-18x+40=0

x²-9x+20=0;

D=81-80=1;

x1=(9+1)/2=5;

x2=(9-1)/2=4;

y1=9-x=4;

y2=9-x=5;

(5;4); (4;5);