Question 5:

Remember: Möbius does not check your method, and matrix computations are fiddly. Make sure to check your answers carefully before submitting. a. Find d such that det A = 0, where A=\left(\begin{array}{lll}

9 & 0 & 8 \\

1 & d & 0 \\

1 & 1 & 1

\end{array}\right) d = _______________ b. Now, and for the remainder of this question, instead set d = −6, so A=\left(\begin{array}{ccc}

9 & 0 & 8 \\

1 & -6 & 0 \\

1 & 1 & 1

\end{array}\right) Calculate the matrix of cofactors for the matrix A. matrix of cofactors= c. Use the information above to find the inverse matrix A-1, employing the method of cofactors. (This part still uses that d = -6.)

A−1= d. Show/hideUse your answer from the previous part to solve the matrix equation \left(\begin{array}{ccc}

9 & 0 & 8 \\

1 & -6 & 0 \\

1 & 1 & 1

\end{array}\right)\left(\begin{array}{l}

x \\

y \\

z

\end{array}\right)=\left(\begin{array}{l}

-1 \\

-4 \\

-3

\end{array}\right) \left(\begin{array}{l}

x \\

y \\

z

\end{array}\right)= Enter your answer as a column vector using the vector/matrix palette tool.