Odpowiedź:
a)
[tex]\left \{ {{x+y=5} \atop {x-y=1}} \right. \\\left \{ {{x+y=5} \atop {x=1+y}} \right.\\ 1+y+y=5\\y=2\\x=1+2\\x=3\\(x,y)=(3,2)\\\left \{ {{3+3-5} \atop {3-2=1}} \right.\\ \left \{ {{5=5} \atop {1=1}} \right.\\ (x,y)=(3,2)[/tex]
b)
[tex]\left \{ {{x=5-y} \atop {x-y=1}} \right.\\ 5-y-y=1\\y=2\\x=5-2\\x=3\\(x,y)=(3,2)\\\left \{ {3=5-2} \atop {3-2=1}} \right.\\ \left \{ {{3=3} \atop {1=1}} \right.\\ (x,y)=(3,2)\\[/tex]
c)
[tex]\left \{ {{x=5-y} \atop {5-y-y=1}} \right.\\ \left \{ {{x=5-y} \atop {y=2}} \right.\\ x==5-2\\x-3\\(x,y)=(3,2)\\\left \{ {{3=5-2} \atop {5-2-2=1}} \right.\\ \left \{ {{3=3} \atop {1=1}} \right.\\ (x,y)=(3,2)[/tex]
Szczegółowe wyjaśnienie:
