uses crt;
var a,b,x:real;
begin
Clrscr;
Writeln('Nhap a,b= ');
Readln(a,b);
If ((a=0 ) and (b=0)) then write('pt vo so nghiem') else if ((a=0) and (b<>0)) then write('pt vo nghiem') else
begin
x:=-b/a;
Write('pt co nghiem x=',x);
Readln;
End;
End.