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 20

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:

Objective Test

An assessment tool designed to measure knowledge, skills, or abilities without subjective judgment.

Criterion-related Validity

The extent to which a measure is related to an outcome, where the validity is determined by comparing the measure against a known criterion or benchmark.

Construct Validity

The extent to which a test or instrument accurately measures the theoretical construct it is intended to assess.

Reliability

The reliability and steadiness of outcomes produced by a measurement tool across multiple instances.