\( 25 + x - 8 y + 3 z \)

The expression \( 25 + x - 8y + 3z \) is a linear combination of the variables \( x \), \( y \), and \( z \). This means that each variable can take any real number value, and the expression results in a real number output. This flexibility makes it applicable in various fields like economics for profit calculations or physics for determining forces. When working with this expression, a common mistake is to forget the impact of coefficients on variables, such as misplacing the negative sign in front of \( 8y \). It's also easy to overlook combining like terms if you end up with an extended expression. Always double-check your signs and group terms carefully!