ext/ply/example/BASIC/linear.bas

   1 1  REM ::: SOLVE A SYSTEM OF LINEAR EQUATIONS
   2 2  REM ::: A1*X1 + A2*X2 = B1
   3 3  REM ::: A3*X1 + A4*X2 = B2
   4 4  REM --------------------------------------
   5 10 READ A1, A2, A3, A4
   6 15 LET D = A1 * A4 - A3 * A2
   7 20 IF D = 0 THEN 65
   8 30 READ B1, B2
   9 37 LET X1 = (B1*A4 - B2*A2) / D
  10 42 LET X2 = (A1*B2 - A3*B1) / D
  11 55 PRINT X1, X2
  12 60 GOTO 30
  13 65 PRINT "NO UNIQUE SOLUTION"
  14 70 DATA 1, 2, 4
  15 80 DATA 2, -7, 5
  16 85 DATA 1, 3, 4, -7
  17 90 END