For this case we have the following system of equations:
[tex]x + y = 5\\x - y = 7[/tex]
From the first equation we have:
[tex]x = 5-y[/tex]
We substitute in the second equation:
[tex]5-y-y = 7\\5-2y = 7[/tex]
We subtract 5 from both sides of the equation:
[tex]-2y = 7-5\\-2y = 2[/tex]
We divide -2 on both sides of the equation:
[tex]y = \frac {2} {- 2}\\y = -1[/tex]
So:
[tex]x = 5-y\\x = 5 - (- 1)\\x = 5 + 1\\x = 6[/tex]
So, the system solution is: [tex](x, y) :( 6, -1)[/tex]
Answer:
See attached image [tex](x, y) :( 6, -1)[/tex]