



 
Hi Paula. 2x3y=9 is not a point, it is a line which represents a function. I think when the question says "find the function for y" it means to convert the equation into the form y = mx + b. Here, m and b are numbers. So it means the same thing as "solve for y". You don't have to have the equation represented as a function of y in order to plot it, but it sure makes things easy. So your assumption is probably correct and your son is meant to use the y = mx + b form to plot the line. So the first step is to convert the equation to that form:
So the equivalent form in y = mx + b form is y = (2/3)x  3. m is the slope, and b is the y intercept. So to plot the line on a graph, you start at the y intercept. The y intercept is the point where the line crosses the y (vertical) axis. So that point is (0, b) which in our case is (0, 3).
Next, you use the slope m = 2/3 to find out where to plot another point. The slope is the "rise" over the Now that you have two points, you can use a ruler to just draw the line through the two points to finish the graph:
Cheers,  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 