Hello, someoneanonymous!
We have: .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
Therefore, is divisible by 19.
1. Show that 21*18^(2x)+36*7^(3x) is divisible by 19 for all positive integers x
2. Find all pairs of odd integers m and n which satisfy the following equation:
m+128n=3mn