{3.29(a)
Dlya proizvol'nyh zadannyh veshestvennyh chisel a,b,c opredelit', imeet li yravnenie
a*x*x+b*x+c=0 hotya by odno veshestvennoe chislo}
program kv(input,output);
var a,b,c:real;
    r:boolean;
begin
    write('vvedite koefficienty a,b,c v a*x*x+b*x+c');
    read(a,b,c);
    r:=(a<>0)and(b*b-4*a*c>=0)or(a=0)and((b=0)and(c=0)or(b<>0));
    write('y yravneniya est''resheniya ',r)
end.