[질문] 3X3행렬의 역행렬구하는공식

A={{a,b,c},{d,e,f},{g,h,i}} aA={{-fh+ei,ch-bi,-ce+bf},{fg-di,-cg+ai,cd-af},{-eg+dh,bg-ah,-bd+ae}} bA=-ceg+bfg+cdh-afh-bdi+aei 최종적으로,A^-1=(1/bA)aA