Expert: Scott A Wilson - 10/14/2010

Question
i am having a lot of trouble with linear equations/models and then graphing them...can you be of assistance in just briefly explaining this to me? thanks.

Answer
On graph paper, the points are each (x,y) where x is the distance from on the x axis from x=0 and y is the distance on the y axis from the center.  The middle of the graph is at (0,0), but sometimes is off to the side on paper.

All lines can be writen in the form y = mx + b.  When this is done, m is the slope and b is the y intercept.  The y intercept is on the y axis, for it is where x = 0.

Suppose we have y = 3x + 5.  For this, 3 is the slope and 5 is the y intercept.  That means that at x = 0, y = 5 and for each unit to the right, y goes up by 5 units.

Thus, if we take x 1 unit to the right,  y will go up by 3 units.  This means that when x gets to 1, y has gone up by 3.  Now x started at 0, so now it is at 1, but y started at 5, so now it is at 8.