p cannot be 2 since both of the expressions on the right side are odd. 4 cases.
1. p∣5p−2p and q∣7q−2q. By Fermat's little theorem, 5^{p}-2^{p}\equiv5-2\equiv3\pmod{p} and 7-2\equiv0\pmod{q}. So, p=3,q=5.
2. p\mid 5^{p}-2^{p} and q\mid 5^{p}-2^{p}. Then p\mid 5^{p}-2^{p}, so p=3. And q\mid 5^{3}-2^{3} implies q\in\{3,37\}.
3. p\mid 7^{q}-2^{q} and q\mid 7^{q}-2^{q}. Again, p\mid 7^{\gcd(q,p-1)}\equiv2^{\gcd(q,p-1)}. Since q> p-1 and q is prime, \gcd(q,p-1)=1. So, p=5.
4. p\mid 7^{q}-2^{q} and q\mid 5^{p}-2^{p}. So, p\mid 7^{\gcd(q,p-1)}-2^{\gcd(q,p-1)} and q\mid 5^{\gcd(p,q-1)}-2^{\gcd(p,q-1)}. Again, \gcd(q,p-1)=1 so p=5. If \gcd(5,q-1)=1, then q\mid 5-2 which is impossible since q\geq p. So, 5\mid q-1, q\neq3 and q\mid 5^{5}-2^{5}. So q is any primitive prime divisor of 5^{5}-2^{5}.