Question 1128691
{{{matrix(4,4,2,   4,  -2,   9,7  , 5,   0,  -1,-4,  6,  -3 ,  1,2  , 5,   7,   1)}}}

the main diagonal is:

{{{matrix(4,4,highlight(2),   4,  -2,   9,7  ,highlight( 5),   0,  -1,-4,  6, highlight( -3) ,  1,2  , 5,   7,  highlight( 1))}}}


{{{2}}},{{{5}}},{{{-3}}},{{{1}}}