PRINT
PRINT "２次方程式：  ａx^2 ＋ ｂx ＋ ｃ ＝ ０"
PRINT
INPUT PROMPT "a, b, c ？   ":a,b,c
PRINT
PRINT "２次方程式：  ";a;"x^2 ＋";b;"x ＋ ";c;" ＝ ０"
PRINT
IF a=0 THEN
   IF b=0 THEN
      IF C=O THEN
         PRINT "   x は すべての数"
      ELSE
         PRINT "係数の入力が間違っています"
      END IF
   ELSE
      PRINT "   x ＝ ";-1*c/b
   END IF
   GOTO 10
END IF
LET D=b^2-4*a*c
IF D=O THEN
   LET x=-1*b/(2*a)
   PRINT "   x ＝ ";x
   PRINT
   PRINT "確かめ："
   PRINT "   ";a;"×";x;"^2  ＋ ";b;"×";x;" ＋ ";c;" ＝ 0"
   PRINT "         ";a*x^2;" ＋ ";b*x;" ＋ ";c;" ＝ 0"
ELSEIF D>O THEN
   LET x1=(-1*b+SQR(D))/(2*a)
   LET x2=(-1*b-SQR(D))/(2*a)
   PRINT "   x ＝ ";x1
   PRINT "   x ＝ ";x2
   PRINT
   PRINT "確かめ："
   PRINT "   ";a;"×";x1;"^2  ＋ ";b;"×";x1;" ＋ ";c;" ＝ 0"
   PRINT "         ";a*x1^2;" ＋ ";b*x1;" ＋ ";c;" ＝ 0"
   PRINT
   PRINT "   ";a;"×";x2;"^2  ＋ ";b;"×";x2;" ＋ ";c;" ＝ 0"
   PRINT "         ";a*x2^2;" ＋ ";b*x2;" ＋ ";c;" ＝ 0"
ELSE
   LET Q=-1*b/(2*a)
   LET W=SQR(-1*D)/(2*a)
   CALL COM(Q,W,Q,W,T1,T2)
   CALL COM(Q,-1*W,Q,-1*W,S1,S2)
   PRINT "   x ＝ ";Q;"＋";W;"×ｉ"
   PRINT "   x ＝ ";Q;"−";W;"×ｉ"
   PRINT
   PRINT "確かめ："
   PRINT "   ";a;"×（ ";Q;"＋";W;"×ｉ) ^ 2  ＋ ";b;"×（ ";Q;"＋";W;"×ｉ) ＋ ";c;" ＝ 0"
   PRINT "         ";a;"×（ ";T1;"＋";T2;"×ｉ)  ＋ ";b;"×（ ";Q;"＋";W;"×ｉ) ＋ ";c;" ＝ 0"
   PRINT
   PRINT "   ";a;"×（ ";Q;"−";W;"×ｉ) ^ 2  ＋ ";b;"×（ ";Q;"−";W;"×ｉ) ＋ ";c;" ＝ 0"
   PRINT "         ";a;"×（ ";S1;"＋";S2;"×ｉ)  ＋ ";b;"×（ ";Q;"−";W;"×ｉ) ＋ ";c;" ＝ 0"
    
END IF
10 PRINT
   PRINT "解の公式：  x ＝ ( −b ± SQR ( b^2−4*a*c ) ) ／ (２× a )"
   PRINT
END

EXTERNAL SUB COM(A1,A2,B1,B2,CO1,CO2)
   LET CO1=A1*B1-A2*B2
   LET CO2=A2*B1+A1*B2
END SUB