Graph the line whose $x$-intercept is 3 and whose $y$-intercept is -1 .

Step 1 ：First, we know that the line crosses the x-axis at (3,0) and the y-axis at (0,-1).

Step 2 ：The slope of the line can be calculated using the formula \(m = \frac{y_2 - y_1}{x_2 - x_1}\).

Step 3 ：Substituting the coordinates of the two points into the formula, we get \(m = \frac{-1 - 0}{0 - 3} = \frac{1}{3}\).

Step 4 ：The equation of the line in slope-intercept form is \(y = mx + b\), where m is the slope and b is the y-intercept.

Step 5 ：Substituting the values of m and b into the equation, we get \(y = \frac{1}{3}x - 1\).

Step 6 ：This is the equation of the line whose x-intercept is 3 and y-intercept is -1.