Question

Is x + y = -4 the linear equation that matches this table of ordered pairs? Explain why or

why not

(-2,-2)
(0, 0)
(2, 2)

Answer 1

Answer: No, it doesn't match

Reason:

One counter-example is to use the 2nd ordered pair to say

x+y = -4

0+0 = -4

0 = -4

Which is false. Therefore, the point (0,0) is not on the line x+y = -4

We could also use the 3rd ordered pair as a counter-example.

x+y = -4

2+2 = -4

4 = -4

This proves (2,2) is not on the line x+y = -4

Choice A is the only ordered pair that works. But we need all 3 ordered pairs to work for the entire statement to be true.