a. \( y=3 x \)

Did you know that the equation \( y=3x \) represents a linear function with a slope of 3? This means that for every unit increase in \( x \), the value of \( y \) increases by 3 units. It’s a straight line that passes through the origin (0,0), which makes it easy to graph! In real-world scenarios, linear equations like \( y=3x \) can model relationships such as speed and distance. For example, if you’re driving at a constant speed of 3 miles per hour, the equation tells you how far you’ll travel over time. It’s a simple yet powerful tool in everything from budgeting to physics!