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