Choose a system of equations with the same solution as the following system: 6x + 2y = −6
3x − 4y = −18

a) 8x + 4y = −4
17x + 2y = −28

b)12x + 4y = 12
21x + 2y = −36

c) 6x + 8y = −36
15x + 6y = −60

d)6x + y = 15
15x − y = −9