Final answer:
The slope of the given line is 3, indicating a rise of 3 units on the y-axis for every 1 unit increase along the x-axis. The slope signifies the steepness and the direction of the line on the graph.
Step-by-step explanation:
The question asks us to determine the slope of a line that has certain characteristics mentioned in the provided description. According to Figure A1, the slope of the line is given as 3. This means that for every increase of 1 unit along the x-axis (horizontal axis), there is a rise of 3 units along the y-axis (vertical axis). In algebra, the slope is often represented by the letter m, and in the equation of a straight line, y = mx + b, m indicates the slope and b signifies the y-intercept, which is the point where the line crosses the y-axis. In this case, the y-intercept b is 9.
The slope of a line is crucial in determining how steep the line is and the direction it slopes. A positive slope such as 3 indicates that the line slopes upwards as one moves from left to right across the graph. It's also important to understand that the slope reflects the rate of change between the two variables represented on the axes. In many physical situations, the slope can represent things such as speed, productivity, or any other rate of change.