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The table shows the number of hours she worked at each job over the course of three weeks.

\begin{tabular}{|l|c|c|c|}
\hline
& Tutoring & Babysitting & \begin{tabular}{c}
Grocery \\
Store
\end{tabular} \\
\hline
Week 1 & 4 & 8 & 6 \\
\hline
Week 2 & 3 & 5 & 4 \\
\hline
Week 3 & 4 & 6 & 4 \\
\hline
\end{tabular}

In week 1, Suzie earned [tex]$\$[/tex]215[tex]$; in week 2, she earned $[/tex]\[tex]$145$[/tex]; and in week 3, she earned [tex]$\$[/tex]170[tex]$. What matrix equation could be used to determine the hourly wage she earns for each job? Fill in the missing elements in the equation.

$[/tex][tex]$
\left[\begin{array}{ccc}
4 & 8 & 6 \\
3 & 5 & 4 \\
4 & 6 & 4
\end{array}\right]
\left[\begin{array}{c}
t \\
b \\
g
\end{array}\right]
=
\left[\begin{array}{c}
215 \\
145 \\
170
\end{array}\right]
$[/tex]$


Sagot :

To determine Suzie's hourly wages for her jobs in tutoring, babysitting, and at the grocery store, we can set up a matrix equation based on the data provided.

The matrix equation we want to solve is of the form [tex]\(Ax = B\)[/tex], where:
- [tex]\(A\)[/tex] is a matrix representing the hours worked each week at each job.
- [tex]\(x\)[/tex] is a vector containing the hourly wages for each job.
- [tex]\(B\)[/tex] is a vector representing the total earnings each week.

Given the details:
- In Week 1, Suzie worked 4 hours tutoring, 8 hours babysitting, and 6 hours at the grocery store.
- In Week 2, she worked 3 hours tutoring, 5 hours babysitting, and 4 hours at the grocery store.
- In Week 3, she worked 4 hours tutoring, 6 hours babysitting, and 4 hours at the grocery store.

And she earned:
- \[tex]$215 in Week 1 - \$[/tex]145 in Week 2
- \[tex]$170 in Week 3 We can form the following equation: \[ \begin{bmatrix} 4 & 8 & 6 \\ 3 & 5 & 4 \\ 4 & 6 & 4 \end{bmatrix} \begin{bmatrix} t \\ b \\ g \end{bmatrix} = \begin{bmatrix} 215 \\ 145 \\ 170 \end{bmatrix} \] Here: - \( \begin{bmatrix} 4 & 8 & 6 \\ 3 & 5 & 4 \\ 4 & 6 & 4 \end{bmatrix} \) is the matrix \(A\) representing the hours worked each week. - \( \begin{bmatrix} t \\ b \\ g \end{bmatrix} \) is the vector \(x\) representing the hourly wages for tutoring (\(t\)), babysitting (\(b\)), and the grocery store (\(g\)). - \( \begin{bmatrix} 215 \\ 145 \\ 170 \end{bmatrix} \) is the vector \(B\) representing the total earnings each week. When we solve this system of linear equations, we find that the hourly wages are: \[ t = 15.00 \] \[ b = 10.00 \] \[ g = 12.50 \] Therefore, Suzie's hourly wages are: - \$[/tex]15.00 per hour for tutoring.
- \[tex]$10.00 per hour for babysitting. - \$[/tex]12.50 per hour for the grocery store.