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Section 1.5 Exercise

For each of the following linear systems, determine whether the system is consistent, and, if so, find the general solutions.
  1. \begin{equation*} \begin{alignedat}{5} \amp{}{}\amp 2x_2\amp {}+{}\amp 2x_3 {}={} \amp -4 \\ 2x_1\amp{}-{}\amp x_2\amp {}+{}\amp 3x_3 {}={} \amp 10 \\ -x_1\amp{}+{}\amp x_2\amp\amp {}={} \amp 8 \\ 3x_1\amp{}+{}\amp 2x_2\amp {}-{}\amp x_3 {}={} \amp -118 \\ \end{alignedat} \end{equation*}
  2. \begin{equation*} \begin{alignedat}{5} -x_1\amp{}+{}\amp x_2\amp \amp \amp {}+{} \amp 2x_4 \amp {}={} \amp -1 \\ 2x_1\amp{}-{}\amp x_2\amp {}+{}\amp 3x_3 \amp {}+{} \amp 3x_4 \amp {}={} \amp 8 \\ \amp{}{}\amp 2x_2\amp {}+{}\amp 2x_3 \amp {}+{} \amp 6x_4 \amp {}={} \amp 4 \\ 3x_1\amp{}+{}\amp 2x_2\amp {}-{}\amp x_3 \amp {}-{} \amp 3x_4 \amp {}={} \amp 1 \\ \end{alignedat} \end{equation*}
  3. \begin{equation*} \begin{alignedat}{5} 2x_1\amp{}-{}\amp x_2\amp {}+{}\amp 3x_3 \amp {}+{} \amp 3x_4 \amp {}={} \amp 8 \\ 3x_1\amp{}+{}\amp 2x_2\amp {}-{}\amp x_3 \amp {}-{} \amp 3x_4 \amp {}={} \amp 0 \\ -x_1\amp{}+{}\amp x_2\amp \amp \amp {}+{} \amp 2x_4 \amp {}={} \amp -1 \\ \amp{}{}\amp 2x_2\amp {}+{}\amp 2x_3 \amp {}+{} \amp 6x_4 \amp {}={} \amp 4 \\ \end{alignedat} \end{equation*}