2x + y - z = -8
2y + 3z = -6
-x + y + z = -4
For the following matrix, which of the following matrix operations would result in a_11 = 1?

Anyone know? is appreciated! will mark brainliest if correct!

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.

What 8/12+8/11 in another way than and improper fraction