Q1. How can I extract elements from a solution set?

For example, consider:

sage: x, y = var('x, y')
sage: solve([x+y==6, x-y==4], x, y)
[[x == 5, y == 1]]

How can I extract these values for x and y so that I can, for
instance, use them as the coefficients for a polynomial f(t)=x+ty so
that I have f(t)=5+1*t?

I believe the solution set is a sequence so I imagine there is some
simple command which allows one to extract the n^th term in the
sequence, no?


Q2. How can I define the set of all primes up to some limit N but
excluding 2 and multiples of some number D?

My failed attempt at this is:

sage: D=some number I define here
sage: def P(N):
         A=set([])
            for i in range(N+1):
                if i in Primes and i/=2 and D%i>0:
                     P=A.add(i)
            return P

I imagine the fixes to these two problems are relatively simple but I
am new to Sage and am having some teething problems.  Any help would
be much appreciated.  Thanks.

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