The Solution:
We are required to determine if the given ordered pair attached to each pair of equations is the solution of the system of equations.
1.

We shall substitute 1 for x and 2 for y.

2.

Substitute -4 for x and 2 for y.

3.

Here, x=5, y=6

Therefore, system1 is a solution
system 3 is not a solution.
system5 is a solution.