9 CLS
10 PRINT "MATRIX INVERSION" 
20 PRINT 
30 DIM A(10,10), B(10,10)
40 PRINT "dIMENSION OF MATRIX"; 
50 INPUT R 
60 PRINT "MATRIX ELEMENTS:" 
70 FOR J=1 TO R 
80 PRINT "ROW"; J 
90 FOR I=1 TO R 
100 PRINT "VALUE COLUMN";I; 
110 INPUT A(J,I)
120 NEXT I 
130 B(J,J)=1 
140 NEXT J 
150 FOR J=1 TO R 
160 FOR I=J TO R 
170 IF A(I,J)<>0 THEN 210 
180 NEXT I 
190 PRINT "SINGULAR MATRIX" 
200 GOTO 500 
210 FOR K=1 TO R 
220 S=A(J,K) 
230 A(J,K)=A(I,K) 
240 A(I,K)=S
250 S=B(J,K) 
260 B(J,K)=B(I,K)
270 B(I,K)=S
280 NEXT K 
290 T=1/A(J,J) 
300 FOR K=1 TO R 
310 A(J,K)=T*A(J,K) 
320 B(J,K)=T*B(J,K) 
330 NEXT K 
340 FOR L=1 TO R 
350 IF L=J THEN 410 
360 T=-A(L,J)
370 FOR K=1 TO R 
380 A(L,K)=A(L,K)+T*A(J,K) 
390 B(L,K)=B(L,K)+T*B(J,K) 
400 NEXT K 
410 NEXT L 
420 NEXT J 
430 PRINT 
440 FOR I=1 TO R 
450 FOR J=1 TO R 
460 PRINT INT(B(I,J)*1000+.5)/1000;" "; 
470 NEXT J 
480 PRINT 
490 NEXT I 
500 END