Solve the system by addition.

2x – 4y = 7,4x + 2y = –1
can you show me how to set it up so I can use this one as a guide.thank you

1 answer

Sure.
2x - 4y = 7
4x + 2y = -1
Double both sides of the last equation.
8x + 4y = -2
Add the first and third equations (both sides separately). This results in
10x = 5
Divide both sides by 2
x = 1/2. Finally substitute x=1/2 into any of the equations
1 - 4y = 7
4y = -6
y = -3/2