Answer:
1 and 3.
Explanation:
The given system of equations
...(1)
... (2)
Here, coefficients of x have same values with opposite signs.
The x-variable will be eliminated when adding the system of equations.
Add (1) and (2), we get
Divide both sides by 4.
Put y=-3 in (1).
Divide both sides by 2.
So, the given system of equations have unique solution, i.e., (-17,-3).
Therefore, the correct options are 1 and 3.