Answer:
Hello!!
For question twelve, is an identity.
For question thirteen, has no solution.
Hope this helps!!
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Step-by-step explanation:
x = 2
3.x + y = 11 (eq 1)
Y = x + 3 (eq 2)
sub 2 into 1
3x + x + 3 = 11
4x + 3 = 11
4x = 8
be the identity matrix. Then pick whatever matrix you like for 
.