\text { a) Find the values of } a \text { for which the matrix } A=\left(\begin{array}{cc} a & 2 \\ -12 & 5-a \end{array}\right) \text { has no inverse.

} Given that B=\left(\begin{array}{cc} 4 & -2 \\ 3 & 1 \end{array}\right) \quad \text { and } \quad C=\left(\begin{array}{cc} -3 & -5 \\ 2 & 4 \end{array}\right) solve the matrix equation 3X +I = - BC, where I is the identity matrix, to find X. ) Consider the following linear system: 3 x-4 y=-27 5 x+12 y=-17 i) Find the inverse matrix A-'. i) Find the solution to the system (3.1) using the inverse matrix method.