The table shows the total cost of purchasing [tex]\(x\)[/tex] same-priced items and a catalog.

[tex]\[
\begin{tabular}{|c|c|}
\hline
\text{Number of Items }(x) & \text{Total Cost }(y) \\
\hline
1 & \$10 \\
\hline
2 & \$14 \\
\hline
3 & \$18 \\
\hline
4 & \$22 \\
\hline
\end{tabular}
\][/tex]

What is the initial value and what does it represent?

A. \[tex]$4, the cost per item
B. \$[/tex]4, the cost of the catalog
C. \[tex]$6, the cost per item
D. \$[/tex]6, the cost of the catalog



Answer :

To determine the initial value and what it represents, let's analyze the given table:

[tex]\[ \begin{array}{|c|c|} \hline \text{Number of Items } (x) & \text{Total Cost } (y) \\ \hline 1 & \$ 10 \\ \hline 2 & \$ 14 \\ \hline 3 & \$ 18 \\ \hline 4 & \$ 22 \\ \hline \end{array} \][/tex]

1. Determine the cost per item:
The change in total cost when purchasing each additional item is consistent:
- From 1 to 2 items: [tex]\( \$ 14 - \$ 10 = \$ 4 \)[/tex]
- From 2 to 3 items: [tex]\( \$ 18 - \$ 14 = \$ 4 \)[/tex]
- From 3 to 4 items: [tex]\( \$ 22 - \$ 18 = \$ 4 \)[/tex]

Therefore, the cost per item is [tex]\( \$ 4 \)[/tex].

2. Determine the initial value:
The initial value is the total cost when [tex]\( x = 0 \)[/tex] (before any items are purchased). The equation representing the total cost [tex]\( y \)[/tex] is [tex]\( y = mx + b \)[/tex], where [tex]\( m \)[/tex] is the cost per item and [tex]\( b \)[/tex] is the initial value.

Using the point [tex]\((1, 10)\)[/tex]:
[tex]\[ y = mx + b \implies 10 = 4 \cdot 1 + b \][/tex]
Solving for [tex]\( b \)[/tex]:
[tex]\[ 10 = 4 + b \implies b = 10 - 4 = 6 \][/tex]

Conclusion:
- The cost per item is [tex]\( \$ 4 \)[/tex].
- The initial value is [tex]\( \$ 6 \)[/tex].

The initial value [tex]\( \$ 6 \)[/tex] represents the cost of the catalog.

So from the given options:
- [tex]\( \$ 4 \)[/tex], the cost per item
- [tex]\( \$ 6 \)[/tex], the cost of the catalog

Correct answers:
- [tex]\( \$ 4 \)[/tex], the cost per item
- [tex]\( \$ 6 \)[/tex], the cost of the catalog