We are told that the dependent variable increases by 1 unit every time the independent variable decreases by 5 units.
slope=1/-5 ⇔ slope=-1/5
y-intercept
Think of the point where a line crosses the y-axis. The x-coordinate of that point is 0, and the y-coordinate is the y-intercept. We know that the value of the function at 0 is 3. Therefore the line intercepts the y-axis at (0,3), and therefore the y-intercept is 3.
Graph
We now have enough information to graph the function. We will start by plotting the y-intercept. Then, we will use the slope to find another point. By connecting these points with a straight line, we will form the graph of our equation.
x-intercept
We can identify the x-intercept by looking at the graph.
The line intercepts the x-axis at (15,0). Therefore, the x-intercept is 15.
