Question 110657: Which of the ordered pairs
(7, 1), (9, 0), (5, –2), (–7, 8)
are solutions for the equation x + 2y = 9?
Hint: There can be more than 1.
Answer by jim_thompson5910(35256)   (Show Source):
You can put this solution on YOUR website!
 Start with the given equation
Let's test the first solution (7,1):
 Plug in  and 
 Simplify. Since the two sides of the equation are equal, this means (7,1) is a solution to
-------Now lets test another solution-------
Let's test the second solution (9,0):
 Plug in  and 
Simplify. Since the two sides of the equation are equal, this means (9,0) is a solution to
-------Now lets test another solution-------
Let's test the third solution (5,-2):
 Plug in  and 
 Simplify. Since the two sides of the equation are not equal, this means (5,-2) is not a solution to
-------Now lets test another solution-------
Let's test the fourth solution (-7,8):
 Plug in  and 
Simplify. Since the two sides of the equation are equal, this means (-7,8) is a solution to
==============================================================================
Answer:
So the following ordered pairs are solutions to
(7,1), (9,0), and (-7,8)
Now let's graph the equation and plot the points (7,1), (9,0), (5,-2), and (-7,8)
Here we can see that the points (7,1), (9,0), and (-7,8) lie on the line (they are the green points). These are the solutions to the equation .
Notice the other possible solutions are points that do not lie on the line. Those ordered pairs do not satisfy the equation
|
|
|
