program Houteishiki1; {$APPTYPE CONSOLE} uses SysUtils; var A,B,C : Real; D,B1,D1 : Real; begin WriteLn('2次方程式 ax^2+bx+c=0 の解'); WriteLn; Write('係数a,b,c (aに 0 を入れると終わり) [a b c] ? '); ReadLn(A,B,C); while A <> 0 do begin D := Sqr(B)-4*A*C; B1 := -B/(2*A); D1 := Sqrt(Abs(D))/(2*A); if D > 0 then WriteLn('実数解: ', B1-D1:0:4, ', ', B1+D1:0:4) else if D = 0 then WriteLn('二重解: ', B1:0:4) else WriteLn('虚数解: ', B1:0:4, '±', D1:0:4, 'i'); WriteLn; Write('係数a,b,c (aに 0 を入れると終わり) [a b c] ? '); ReadLn(A,B,C); end; end.