Answer:
Step-by-step explanation:
[tex]\underline{+\left\{\begin{array}{ccc}x+y=12\\x-y=2\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad2x=14\qquad\text{divide both sides by 2}\\.\qquad x=7\\\\\text{Put it to the first equation:}\\\\7+y=12\qquad\text{subtract 7 from both sides}\\y=5[/tex]