NEED HELP
Given the system of equations presented here:

4x + y = 4
2x + 7y = 28

Which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated?

Multiply the second equation by −1 to get −2x − 7y = −28
Multiply the second equation by −4 to get −8x − 28y = −112
Multiply the first equation by −7 to get −28x − 7y = −28
Multiply the first equation by −2 to get −8x − 2y = −8

Question

NEED HELP 
Given the system of equations presented here:

4x + y = 4
2x + 7y = 28

Which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated?

 Multiply the second equation by −1 to get −2x − 7y = −28
 Multiply the second equation by −4 to get −8x − 28y = −112
 Multiply the first equation by −7 to get −28x − 7y = −28
 Multiply the first equation by −2 to get −8x − 2y = −8

welshfella · Answer

you need to change the value and sign of the x term or the y-term so on addition one of the variables is eliminated

welshfella · Answer

HinT: multiply the first equation by a negative number

anonymous · Answer

It is C :)

anonymous · Answer

Do you know why?