Given the system of equations presented here:

2x + 4y = 14
4x + y = 20

which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? (5 points)

a
multiply the second equation by −4 to get −16x − 4y = −80

b
multiply the second equation by −1 to get −4x − y = −20

c
multiply the first equation by 2 to get 4x + 8y = 28

d
multiply the first equation by −1 to get −2x − 4y = −14