Question 70059
It depends upon the form in which the equation of the lines are given.  


If the equation is in the form of y=mx+b, then the easiest way to graph the line is using the slope and y intercept.  For details see my Lesson Plan called "Graphing by Slope-Intercept Method" in Graphs. 


When the equation of the line is in the form y=mx+b, then the coefficient of x is always the slope, which can be written as a fraction as RISE over RUN.   


For example, {{{y = 3x-2}}} means that the slope is {{{3/1}}}.  This means that the RISE is UP 3, and the RUN is right 1 unit.  Start by graphing the y intercept which is DOWN 2 units on the y-axis.  Then with your pencil on that point at (0,-2), move UP 3, then from there go RIGHT 1, and put a point.  Then connect the two points that you just plotted with a straight line.  That's it!!


For a line with a positive slope, it always goes UPHILL, but if it has a negative slope, then it goes DOWNHILL (it leans to the left!).  See lesson plan for more details.


If the equation is in the form of an x-term plus (or minus)a y term--this iw what we call standard form--that is Ax + By = C, then it's usually easiest to find the x intercept and y intercept and connect these two points.  For detailed explanation of this, see my other Lesson Plan "Graphing Equations in Standard Form by Two-Intercept Method in Graphs." 


To see a comparison of the two methods listed above, see "Graphing Equations in Standard Form by Two-Intercept Method in Graphs. "


R^2 at SCC