How do you solve #x-3y=-9# and #x+3y=3# by graphing?
1 Answer
Solution is
Draw the two graphs
Explanation:
You have two equations,
To plot this on a graph, do some transformation so that you have just
Part 1
You need to get those equations into the form
For the first equation,
Add 9 to both sides.
Add 3y to both sides.
Dividing both sides by 3, you get
For the second one, you do the same thing
Subtracting x from both sides,
Then divide both sides by 3
Part 2
Plot these two equations on the same graph
graph{(x-3y+9)(x+3y-3)=0 [-10, 10, -5, 5]}
The coordinates of where those two lines cross will be your answer. Which will be
Here's why the coordinates of where the two lines cross is the answer:
What the line for
So for instance, if you find the point
So if you want to find a pair of numbers
The same thing applies for more than one line. Since a point that lies on some line