Calculate the determinant.
#1. \(\begin{vmatrix} -1 & -1\\-7 & -7\\\end{vmatrix}\)
#2. \(\begin{vmatrix} -8 & 4\\5 & -6\\\end{vmatrix}\)
#3. \(\begin{vmatrix} 3 & 3 & 6\\3 & -4 & -29\\2 & -1 & -11\\\end{vmatrix}\)
Find the inverse of the given matrix or state that it is singular.
#4. \(\begin{bmatrix} -9 & 0\\8 & 0\\\end{bmatrix}\)
#5. \(\begin{bmatrix} -8 & 2\\-10 & 4\\\end{bmatrix}\)
#6. \(\begin{bmatrix} -5 & 7 & 6\\1 & -9 & 4\\6 & -5 & 1\\\end{bmatrix}\)