Apair of equations is shown below:

y = 7x − 9
y = 3x − 1

part a: in your own words, explain how you can solve the pair of equations graphically. write the slope and y-intercept for each equation that you will plot on the graph to solve the equations. (6 points)

part b: what is the solution to the pair of equations? (4 points)

If you graph y=7x-9 and y=3x-1 the two lines will intersect at one point.  That is how you graphically "solve" the system of equations.

Both of these lines are of the form y=mx+b where m is the slope and b is the y-intercept.

So for y=7x-9, the slope is 7 and the y-intercept is -9

For  y=3x-1, the slope is 3 and the y-intercept is -1



The solution for this system occurs when both coordinates are equal to each other so we can say:

7x-9=3x-1  subtract 3x from both sides

4x-9=-1  add 9 to both sides

4x=8  divide both sides by 4

x=2, making y=3x-1 become:

y=3(2)-1=6-1=5, so the solution to the system of equations is:

(2,5)

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