a=1;b=0;c=-1;

Wersja nr 1

Δ=b*b-4*a*c;
If[a≠0&&Δ≥0,x1=(-b-Sqrt[Δ])/(2*a);x2=(-b+Sqrt[Δ])/(2*a);
Print[" rownanie kwadratowe:  a= ",a,", b= ",b,", c= ",c];
Print[" x1= ",x1,", x2= ",x2];,
If[a==0,
If[b≠0,
x1=-c/b;
Print[" rownanie liniowe:  a= ",a,", b= ",b,", c= ",c];
Print[" x1= ",x1];,
If[c≠0,
Print[" a= ",a,", b= ",b,", c= ",c];Print[" sprzecznosc "];,
Print[" a= ",a,", b= ",b,", c= ",c];
Print[" tozsamosc: 0 == 0"];
]],
If[Δ<0,Print[" a= ",a,", b= ",b,", c= ",c];
Print[" Δ= ",Δ];
Print[" brak rozwiazan rzeczywistych "];]
]
]

Wersja nr 2

If[a==0,If[b==0,If[c==0,Print[" a= ",a,", b= ",b,", c= ",c];
Print[" tozsamosc: 0 == 0"];,
Print[" a= ",a,", b= ",b,", c= ",c];
Print[" sprzecznosc "];
],x1=-c/b;
Print[" rownanie liniowe:  a= ",a,", b= ",b,", c= ",c];
Print[" x1= ",x1]],If[b*b-4*a*c≥0,x1=(-b-Sqrt[b*b-4*a*c])/(2*a);x2=(-b+Sqrt[b*b-4*a*c])/(2*a);
Print[" rownanie kwadratowe:  a= ",a,", b= ",b,", c= ",c];
Print[" x1= ",x1,", x2= ",x2];,Print[" rownanie kwadratowe:  a= ",a,", b= ",b,", c= ",c];Print[" Δ= ",b*b-4*a*c];
Print[" brak rozwiazan rzeczywistych "]]];