See attached.
When graphing equations presented in standard form, it is often convenient to convert them to intercept for. You do this by dividing by the constant on the right, and expressing the x- and y-coefficients as denominators:
... x/(x-intercept) + y/(y-intercept) = 1
Dividing your equation by 48, you get ...
... x/12 + y/(-8) = 1
That is, the intercepts of the line are (12, 0) and (0, -8). A line through these points will be the graph of the equation.