Explanation:
any ordered pair is a solution, if we can use its coordinates in the equation, and the equation stays true.
for x - 3y = 6
1. (3, -1)
3 - 3×-1 = 6
3 + 3 = 6
6 = 6
true, this is a solution.
2. (0, 2)
0 - 3×2 = 6
-6 = 6
false, this is not a solution.
3. (3, 1)
3 - 3×1 = 6
3 - 3 = 6
0 = 6
false, this is not a solution.