2:2

If you mean the ratio 2:2, it simplifies to 1:1.

Reason: divide both terms by their greatest common divisor, gcd(2,2) = 2 → (2/2):(2/2) = 1:1.

Also equivalent: 2:2 = 3:3 = 4:4 = … = 1.0 (as a fraction, 2/2 = 1). If you meant something else, tell me the context.