A=⎣⎡149376528⎦⎤
⎣⎡149376528100010001⎦⎤ R2=R2−4R1
⎣⎡1093−565−1881−40010001⎦⎤ R3=R3−9R1
⎣⎡1003−5−215−18−371−4−9010001⎦⎤ R2=−R2/5
⎣⎡10031−21518/5−3714/5−90−1/50001⎦⎤ R1=R1−3R2
⎣⎡10001−21−29/518/5−37−7/54/5−93/5−1/50001⎦⎤ R3=R3+21R2
⎣⎡100010−29/518/5193/5−7/54/539/53/5−1/5−21/5001⎦⎤ R3=5R3/193
⎣⎡100010−29/518/51−7/54/539/1933/5−1/5−21/193005/193⎦⎤ R1=R1+29R3/5
⎣⎡100010018/51−44/1934/539/193−6/193−1/5−21/19329/19305/193⎦⎤ R2=R2−18R3/5
⎣⎡100010001−44/19314/19339/193−6/19337/193−21/19329/193−18/1935/193⎦⎤We are done. On the left is the identity matrix. On the right is the inverse matrix.
A−1=⎣⎡−44/19314/19339/193−6/19337/193−21/19329/193−18/1935/193⎦⎤
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