program p19;
Uses Crt;

var a1,b1,a2,b2,x,y:real;

begin
clrscr;
write('Zadej parametr a1 : ');readln(a1);
write('Zadej parametr b1 : ');readln(b1);
write('Zadej parametr a2 : ');readln(a2);
write('Zadej parametr b2 : ');readln(b2);
if (a1=a2) then
  if (b1=b2) then
  begin
    writeln('Rovnice maji nekonecne mnoho reseni');
    writeln('Napr. usporadana dvojice [0,',b1:4:2,']');
  end
  else writeln ('Rovnice nemaji zadne reseni')
else
  begin
  x:=(b2-b1)/(a1-a2);
  y:=a1*x+b1;
  writeln('Resenim je jedna uporadana dvojice [',x:4:2,',',y:4:2,']');
  end;
repeat until keypressed;
end.