Example 5.4.10 Deciding to Use Substitution versus Elimination

Decide which method would be easiest to solve the systems of linear equations: substitution or elimination.

  1. \(\left\{ \begin{alignedat}{4} 2x \amp {}+{} \amp 3y \amp {}={} \amp -11 \\ 5x \amp {}-{} \amp 6y \amp {}={} \amp 13 \\ \end{alignedat} \right.\)

  2. \(\left\{ \begin{alignedat}{4} x \amp {}-{} \amp 7y \amp {}={} \amp 10 \\ 9x \amp {}-{} \amp 16y \amp {}={} \amp -4 \\ \end{alignedat} \right.\)

  3. \(\left\{ \begin{alignedat}{4} 6x \amp {}+{} \amp 30y \amp {}={} \amp 15 \\ 4x \amp {}+{} \amp 20y \amp {}={} \amp 10 \\ \end{alignedat} \right.\)

  4. \(\left\{ \begin{alignedat}{1} y\amp {}={} 3x {}-{} 2 \\ y\amp {}={} 7x {}+{} 6 \\ \end{alignedat} \right.\)

Explanation
in-context