Question

Which of the following matrix equations correctly represents this system of equations?

4x+5y=-9
x+3y=-4

a. [ 4 5 ] x= [ -9 ]
1 3 -4

b. [ 4 -5 ] x= [ -9 ]
1 -3 -4

c. [ -4 5 ] x= [ -9 ]
-1 3 -4

d. [ 5 4 ] x= [ -1 ]
3 1 -1