Its A
When you multiply a constant k to a matrix, you multiply all the corresponding numbers in the matrix by k.
So 3A would be = 3 9
15 6
and 2b would be = 8 18
0 6
Now subtract it. to get your answer
Y = 7^3 + 1 is a constant value, all of the others include an x variable in the form of a linear function.
The pacific timezone is 3 hours ahead so its 1:00 Am
