x=3 and y=2x-1

Question

How would I solve this to graph?

Answer 1

Let's start with the easier line first, X = 3.

 

The line x = 3 is a vertical line, crossing the x-axis at 3.  The line is not dependent on the y value, thus it crosses through them all.

 

y = 2x-1 is also a simple line to plot.  First, we find the y-intercept, where the line crosses through the y-axis.  This is marked by the -1, as it is the 'b' in the form, y=mx+b.  The m in this equation is the slope, or the number of units to move right per one unit up.  In this case, the slope is 2.

 

To find where these lines intersect, substitute 3 in for the x in the second line.  y = (2)(3)-1.  y= 6-1... y=5.

 

Thus, these lines intersect at (3,5).