Chapter 9, Problem 7P

Given the equations

$\begin{array}{l}0.5x_1-x_2=-9.5\\ 1.02x_1-2x_2=-18.8\end{array}$

(a) Solve graphically.

(b) Compute the determinant.

(c) On the basis of (a) and (b), what would you expect regarding the system's condition?

(d) Solve by the elimination of unknowns.

(e) Solve again, but with $a_{11}$ modified slightly to 0.52. Interpret your results.