Conditions for a system of linear equations to have a unique solution

Q. $4(81+x)=\left(3k\right)x$
In the above equation, $k$ is a constant. For what value of $k$, is there a unique solution to the equation?

1. Any real value
2. Any real value except 4/3
3. Any real value between -4/3 and 4/3
4. k = 4/3

Q. -6x + 4y = 2 ;
3x + 2y = -1
Consider the system of equations above. If (x, y) is a solution of the equations above, then how many possible values are there for (x, y) ?

1. No solution
2. Infinitely many solutions
3. One solution
4. None of the above

Q.

If the equations in a system of two linear equations in two variables are graphed, each graph will be a line. Which of the following System of Linear equations will have only one solution ?

1. Parallel lines
2. Coincidental lines
3. Intersecting lines
4. All of the above