program giaipb1; 
uses crt; 
var a,b:real; 
begin 
clrscr; 
writeln('Chuong Trinh Giai PT bac 1: ax+b=0'); 
writeln('Nhap a va b'); readln(a,b); 
If (a=0) and (b<>0) then writeln('Phuong trinh vo nghiem'); 
If (a=0) and (b=0) then writeln('Phuong trinh co vo so nghiem'); 
If (a<>0) and(b<>0) then writeln('Phuong trinh co nghiem x=',(-b)/a:4:2); 
readln; 
end.