Tolong dijawab no 1 dan 2 mba mas

Tolong dijawab no 1 dan 2 mba mas

A= $left[begin{array}{cc}7&5&\6&8&end{array}right]$ = 56 – 30 = 26

$=left[begin{array}{ccc}-4&-6&7\2&-6&4\0&2&-2end{array}right] -left[begin{array}{ccc}0&4&3\-2&0&-5\-8&-2&4end{array}right] =left[begin{array}{ccc}-4&-10&4\4&-6&9\8&4&-6end{array}right]\=left[begin{array}{ccc}-4&-10&4\4&-6&9\8&4&-6end{array}right] /2=left[begin{array}{ccc}-2&-5&2\2&-3&9/2\4&2&-3end{array}right]$