Consider the Augmented Matrix $\left[ \begin{array} { l l : l } 1 & - 1 & 2 \\8 & - 6 & 4\end{array} \right]$

question 249

Multiple Choice

Consider the augmented matrix $\left[ \begin{array} { l l : l } 1 & - 1 & 2 \\8 & - 6 & 4\end{array} \right]$ . Which of the following matrices shows the elementary row operation $- 8 R _ { 1 } + R _ { 2 }$ ?

• A) \(\left[ \begin{array} { c c : c }
• 1 & - 1 & 2 \\
• 0 & - 14 & - 12
• \end{array} \right]\)
• B) \(\left[ \begin{array} { l l : l }
• 1 & - 1 & 2 \\
• 0 & - 2 & 20
• \end{array} \right]\)
• C) \(\left[ \begin{array} { c c : c }
• 1 & - 1 & 2 \\
• 0 & 2 & - 12
• \end{array} \right]\)
• D) none of these

---

Definitions:

River Valley

a long, narrow region carved by river erosion, often surrounded by hills or mountains.

Krakatau

An Indonesian volcanic island known for its catastrophic eruption in 1883, significantly impacting global climate and producing loud noises heard thousands of miles away.

Indonesia

A Southeast Asian country consisting of thousands of volcanic islands, known for its diverse cultures, languages, and ecosystems.

Pyroclastic Flow

A fast-moving current of hot gas and volcanic materials (such as ash and rock fragments) that flows down the side of a volcano during an explosive eruption.