Question 1069448
Add the two equations together to eliminate y,
{{{x+y+x-y=2b+2a}}}
{{{2x=2(a+b)}}}
{{{x=a+b}}}
Now find y,
{{{x+y=2b}}}
Substituting,
{{{a+b+y=2b}}}
{{{y=2b-b-a}}}
{{{y=b-a}}}