SOLUTION: Which of the ordered pairs (3, 1), (0, –4), (–4, 0), (–3, –7)are solutions for the equation x – y = 4?

Algebra ->  Systems-of-equations -> SOLUTION: Which of the ordered pairs (3, 1), (0, –4), (–4, 0), (–3, –7)are solutions for the equation x – y = 4?       Log On


   

Question 112863: Which of the ordered pairs
(3, 1), (0, –4), (–4, 0), (–3, –7)are solutions for the equation
x – y = 4?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x-y=4 Start with the given equation


Let's test the first solution (3,1):


%283%29-%281%29=4 Plug in x=3 and y=1


2=4 Simplify. Since the two sides of the equation are not equal, this means (3,1) is not a solution to x-y=4



-------Now lets test another solution-------



Let's test the second solution (0,-4):


%280%29-%28-4%29=4 Plug in x=0 and y=-4


4=4 Simplify. Since the two sides of the equation are equal, this means (0,-4) is a solution to x-y=4



-------Now lets test another solution-------



Let's test the third solution (-4,0):


%28-4%29-%280%29=4 Plug in x=-4 and y=0


-4=4 Simplify. Since the two sides of the equation are not equal, this means (-4,0) is not a solution to x-y=4



-------Now lets test another solution-------



Let's test the fourth solution (-3,-7):


%28-3%29-%28-7%29=4 Plug in x=-3 and y=-7


4=4 Simplify. Since the two sides of the equation are equal, this means (-3,-7) is a solution to x-y=4


==============================================================================
Answer:
So the following ordered pairs are solutions to x-y=4

(0,-4) and (-3,-7)

Now let's graph the equation x-y=4 and plot the points (3,1), (0,-4), (-4,0), and (-3,-7)

Here we can see that the points (0,-4) and (-3,-7) lie on the line (they are the green points). These are the solutions to the equation x-y=4.
Notice the other possible solutions are points that do not lie on the line. Those ordered pairs do not satisfy the equation x-y=4