Question 116993: Please help.
Which of the ordered pairs is a solution for the equation 2x - 4y = 8
A) (-4, -2), B) (0, -2), C) (-4, 0) D) (0, 2)
Thanks
JMS
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 (-4,-2):
 Plug in  and 
 Simplify. Since the two sides of the equation are not equal, this means (-4,-2) is not a solution to
-------Now lets test another solution-------
Let's test the second solution (0,-2):
 Plug in  and
 Simplify. Since the two sides of the equation are equal, this means (0,-2) is a solution to
-------Now lets test another solution-------
Let's test the third solution (-4,0):
 Plug in and 
 Simplify. Since the two sides of the equation are not equal, this means (-4,0) is not a solution to
-------Now lets test another solution-------
Let's test the fourth solution (0,2):
 Plug in and 
Simplify. Since the two sides of the equation are not equal, this means (0,2) is not a solution to
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Answer:
So the following ordered pairs are solutions to
(0,-2)
Now let's graph the equation and plot the points (-4,-2), (0,-2), (-4,0), and (0,2)
Here we can see that the point (0,-2) 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
So this means B) is the answer.
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