The two end digits cannot be even because subtracting one from the other would be an even difference. Explore the odd choices.
123, 345, 567, 789
find three consecutive positive integers such that 4 times the first 13 more than the third.
2 answers
n-1 , n , n+1
4(n-1)-13 = n+1
4 n - 4 - 13 = n+1
3 n = 18
n = 6
5, 6, 7
4(n-1)-13 = n+1
4 n - 4 - 13 = n+1
3 n = 18
n = 6
5, 6, 7