Question

If p is prime and n is even such as that p+n =47 and p×n=210 what is the value of n?

Answer 1

p+n=47
pn=210
p=47-n
n(47-n)=210
47n-n^2-210=0
n^2 - 47n +210 = 0
(n-5)(n-42)=0
n = 5 or 42.  Since we are given n is even we take n = 42
then p = 5