Question 799
Well, the first thing to do is write out what we know as expressions:

{{{x = 5+2y}}}
{{{x+y=35}}}

Then, we can substitute the first equation into the second to get:

{{{(5+2y) + y = 35}}}

{{{5+3y=35}}}
{{{3y=30}}}
{{{y=10}}}

Then, substitute this value for y back into one of the original 2. I'm going to use the second one.

{{{x+10=35}}}
{{{x=25}}}

The 2 numbers are 10 and 25.