Touba M. answered 02/16/20
B.S. in Pure Math with 20+ Years Teaching/Tutoring Experience
Hi Clarissa,
Your question is not very clear.
You need to know determinant of coefficient or you need to solve this system by matrix!
If your question is only finding determinate, IT IS [2 -1]
the correct answer is d. [ 3 2]
I hope it is useful.