Define by using the set-builder notation by using the condition as predicate logic.

We can only use these operations + and *

1) Nonnegative numbers that are divisors of 42.

2) The set pairs of consecutive integers that are even. For example (24, 26) or (30, 28) - These pairs would hold.

What I have is this:

1. {x | x * y = 42, x,y N} or {x | (x,y) N*N and x*y = 42}

2. { (2x,2y) | y = x+2 or x = y+2, x,y Z }

Please give me your opinion or offer another better solution. Thank you!