When the mortgage is completely paid off or Mark in Lynn house it will be 6 times as old as it is now if they have 35 years left on the mortgage how old is the house right now?

Let
x -----> how old is the house right now
so
In 35 years
we have that
(x+35)=6x
solve for x
6x-x=35
5x=35
x=7 years
Therefore