It is convenient to let a calculator do the math.
.. (x, y) = (0, 3) . . . . . your 3rd selection
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I prefer using the RREF function to put the augmented matrix into reduced row-echelon form. If the equations are dependent or inconsistent, using that method tells you so without giving a matrix inversion error.
Answer:
B and C
When you divide 64000 by 2 and 480000 by 15, they all equal 32000.
1.04(10^4) + 5.6(10^2)
1.04(10000) + 5.6(100)
10400 + 560
10960