Algebra Practice Test 2025 – Complete Exam Preparation

A linear function can be identified by its standard form, which is expressed in the format y = mx + b, where m represents the slope and b is the y-intercept. This indicates that the graph of a linear function will produce a straight line when plotted on a coordinate grid.

The function represented by "3x + 1" fits this description perfectly. It has a slope of 3 and a y-intercept of 1, meaning it increases at a constant rate and graphs as a straight line. This consistent rate of change is a hallmark of linear functions.

On the other hand, the other options do not meet the criteria for linearity. The option "x²" results in a parabolic curve, indicating that it changes direction and does not have a constant slope. For "y = 5," although it represents a horizontal line, it is a special case considered a linear function, but not in the same way as "3x + 1" in terms of having an 'x' component affecting slope. Lastly, "x³" is a cubic function, which also curves and cannot be graphed as a straight line.

Thus, "3x + 1" is the only option that clearly and unequivoc