can anyone help me with these 2 super hard questions...

1. If n is positive integer what is the number of solutions (x,y) (with x and y postive integers) to the equation

1/x +1/y =1/n

2. let p be an odd prime, and i be an integer, 0<= i <= p-2. show that 1^i +2^i +3^i +.....+ (p-1)^i = 0 (mod p)