Question 1111018
{{{(1/x  +1/y) =7 }}}


{{{(1/x  -1/y) =3 }}}

add the two equations
we get
2/x = 10

x= 2/10
x=1/5

If x= 1/5 then 
1/y =7-5

1/y = 2

y= 1/2