​Use the Matrix Capabilities of a Graphing Utility to Solve $$\left\{ \begin{array} { l l } - 14 x + 14 y + 21 z & = 10 \\7 x - 7 y & = - 5 \\7 x + 28 z & = 20\end{array} \right.$$

question 58

Multiple Choice

​Use the matrix capabilities of a graphing utility to solve the following system of linear equations:​ $$\left\{ \begin{array} { l l } - 14 x + 14 y + 21 z & = 10 \\7 x - 7 y & = - 5 \\7 x + 28 z & = 20\end{array} \right.$$ ​

• A)​ \[\left[ \begin{array} { l }
• x \\
• y \\
• z
• \end{array} \right] = \left[ \begin{array} { c }
• \frac { 20 } { 7 } \\
• \frac { 25 } { 7 } \\
• 0
• \end{array} \right]\] ​
• B)​ \[\left[ \begin{array} { l }
• x \\
• y \\
• z
• \end{array} \right] = \left[ \begin{array} { c }
• \frac { 10 } { 7 } \\
• 0 \\
• \frac { - 15 } { 7 }
• \end{array} \right]\]
• C)​ \[\left[ \begin{array} { l }
• x \\
• y \\
• z
• \end{array} \right] = \left[ \begin{array} { c }
• \frac { - 15 } { 7 } \\
• \frac { 10 } { 7 } \\
• \frac { 5 } { 7 }
• \end{array} \right]\]
• D)​ \[\left[ \begin{array} { l }
• x \\
• y \\
• z
• \end{array} \right] = \left[ \begin{array} { c }
• \frac { 5 } { 7 } \\\\
• \frac { - 20 } { 7 } \\\\
• \frac { 10 } { 7 }
• \end{array} \right]\]
• E)​ \[\left[ \begin{array} { l }
• x \\
• y \\
• z
• \end{array} \right] = \left[ \begin{array} { c }
• \frac { - 15 } { 7 } \\\\
• \frac { - 10 } { 7 } \\\\
• \frac { 10 } { 7 }
• \end{array} \right]\]

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Definitions:

Monopolist

A monopolist is a sole producer or supplier of a particular good or service in the market, having significant control over pricing and market conditions.

Marginal Revenue

Marginal Revenue is the additional income gained from selling one more unit of a good or service, crucial for understanding profit maximization.

Second Unit

An additional or backup unit or system that serves as a replacement or supplement to the original.

Price-Searcher Markets

Markets where sellers have some discretion over the price of their products due to a lack of perfect competition.