Use Inverses to Solve Matrix Equations
Write the Linear System $$\begin{array} { l } 8 x + 4 y = 20 \\3 x + 5 y = 4\end{array}$$

question 55

Multiple Choice

Use Inverses to Solve Matrix Equations
Write the linear system as a matrix equation in the form AX = B, where A is the coefficient matrix and B is the
constant matrix.
- $$\begin{array} { l } 8 x + 4 y = 20 \\3 x + 5 y = 4\end{array}$$

• A)\( \left[\begin{array}{ll}8 & 4 \\ 3 & 5\end{array}\right]\left[\begin{array}{l}x \\ y\end{array}\right]=\left[\begin{array}{l}20 \\ 4\end{array}\right] \)
• B)\( \left[\begin{array}{cc}20 & 4 \\ 4 & 3\end{array}\right]\left[\begin{array}{l}x \\ y\end{array}\right]=\left[\begin{array}{l}8 \\ 5\end{array}\right] \)
• C)\( \left[\begin{array}{ll}8 & 3 \\ 4 & 5\end{array}\right]\left[\begin{array}{l}x \\ y\end{array}\right]=\left[\begin{array}{l}20 \\ 4\end{array}\right] \)
• D)\( \left[\begin{array}{ll}8 & 4 \\ 5 & 3\end{array}\right]\left[\begin{array}{l}x \\ y\end{array}\right]=\left[\begin{array}{l}4 \\ 20\end{array}\right] \)

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Definitions:

Epithalamus

A portion of the diencephalon in the brain, involved in linking the limbic system to other parts of the brain and regulating hormones and circadian rhythms.

Habenula

The habenula is a small region in the brain involved in regulating sleep-wake cycles, reproductive behavior, and stress responses.

Pineal Gland

is a small endocrine gland in the brain involved in the production of melatonin, regulating sleep patterns.

Mammillary Bodies

Paired structures in the brain involved in memory function, part of the limbic system.