Lets say I have the following matrix :
$$
 \left[\begin{array}{cc}
 z & y & x & w \\
 s-a & t-b & u-c & v-d \\
 a & b & c & d \\
 3s & 3t & 3u & 3v \\
 \end{array} \right]
$$
How would I go about demonstrating whether or not this matrix can be inverted?
I've been ready about the (many) criteria for inverting a matrix and yet I just can't figure this out. All I know is that it's det=-30 from a previous question.