Charlie bikes 9 miles every day.
\begin{tabular}{|c|c|c|c|c|c|}
\hline
Days [tex]$(d)$[/tex] & 1 & 2 & 3 & 4 & 5 \\
\hline
Miles [tex]$(m)$[/tex] & 9 & 18 & 27 & 36 & 45 \\
\hline
\end{tabular}

Which equation models the situation?

A. [tex]$9 = d m$[/tex]
B. [tex]$d = 9 m$[/tex]
C. [tex]$9 d = m$[/tex]
D. [tex]$d = 9 + m$[/tex]



Answer :

Let's analyze the information given and the relationships observed.

Charlie bikes 9 miles every day. Looking at the table provided:

[tex]\[ \begin{tabular}{|c|c|c|c|c|c|} \hline Days $(d)$ & 1 & 2 & 3 & 4 & 5 \\ \hline Miles $(m)$ & 9 & 18 & 27 & 36 & 45 \\ \hline \end{tabular} \][/tex]

It is evident that each day's miles can be expressed as follows:

- On day 1: [tex]\( m = 9 \times 1 = 9 \)[/tex]
- On day 2: [tex]\( m = 9 \times 2 = 18 \)[/tex]
- On day 3: [tex]\( m = 9 \times 3 = 27 \)[/tex]
- On day 4: [tex]\( m = 9 \times 4 = 36 \)[/tex]
- On day 5: [tex]\( m = 9 \times 5 = 45 \)[/tex]

From this pattern, we can observe a linear relationship between the number of days ([tex]\(d\)[/tex]) and the miles ([tex]\(m\)[/tex]). For each day, the miles are a multiple of 9 times the days.

To express this relationship algebraically, we see that:

[tex]\[ m = 9 \times d \][/tex]

Thus, the equation that models the situation must be:

[tex]\[ 9d = m \][/tex]

or more formally written as:

[tex]\[ m = 9d \][/tex]

Matching this with the choices provided:

1. [tex]\( 9 = dm \)[/tex]
2. [tex]\( d = 9m \)[/tex]
3. [tex]\( 9d = m \)[/tex]
4. [tex]\( d = 9 + m \)[/tex]

The correct equation that models this situation is:

[tex]\[ \boxed{9d = m} \][/tex]