Let A,B,C,D,E be integers, B=0 and F=AD2−BCD+B2E=0. Prove that the number N of pairs of integers (x,y) such that Ax2+Bxy+Cx+Dy+E=0, satisfies N≤2d(∣F∣), where d(n) denotes the number of positive divisors of positive integer n. quadraticsDiophantine Equations