What property is this 17z z 17z 1z?

The expression "17z z 17z 1z" seems to represent a polynomial or algebraic expression involving the variable ( z ). It can be simplified by combining like terms. If it represents ( 17z^2 + 17z + z ), this can further be simplified to ( 17z^2 + 18z ). The property being illustrated here is the combination of like terms in polynomial expressions.