let l and m are positive integer solutions
then l+m=p and lm=q
therefore lm is a prime then l or m is a prime an d the other is 1
let l=1 then 1+ m=p
so m and p are 2 consecutive prime numbers
but we know that 2 and 3 are the only consecutive primes
then m=2 and l-1
so p=3 and q=2