For what value(s) of aaa does the system {x+2y=32x+ay=6\begin{cases} x + 2y = 3 \\ 2x + ay = 6 \end{cases}{x+2y=32x+ay=6 have a unique solution?
a≠4a \neq 4a=4
a=4a = 4a=4
a≠0a \neq 0a=0
For any value of aaa