Algebraic Proof

Maths

What is the result of 334543 + 554567 + 66567 + 55456 ?

What is the result of (odd x even) + (odd + even)

What is the result of (odd + odd) + (even x odd) + (even + odd + odd)

Is the value of 2n always odd, always even, or either?

Is the value of 4n - 2 always odd, always even, or either?

Is the value of 3n + 1 always odd, always even, or either?

What operation could I perform to 4n + 1 to make it always even?

What operation could I perform to n + 4 to make it always even?