Chapter 11.CR, Problem 66E

To determine

(a)

To find:

System of linear equation satisfying given conditions.

To determine

(b)

To find:

Matrix equation of the form $AX=B$.

To determine

(c)

To find:

The inverse matrix $A^{-1}$, and hence the solution of matrix equation $\left[\begin{array}{cc}20& 50\\ 1& 1\end{array}\right]\left[\begin{array}{c}x\\ y\end{array}\right]=\left[\begin{array}{c}600\\ 18\end{array}\right]$.