Write and evaluate the expression. Then, select the correct answer.

A number squared decreased by six. Evaluate when [tex][tex]$c=7$[/tex][/tex].

[tex]\[
\begin{tabular}{|c|c|}
\hline
\text{Key Words} & \text{Replace With} \\
\hline
\text{a number} & $c$ \\
\hline
\text{squared} & \text{exponent is 2} \\
\hline
\text{decreased by} & - \\
\hline
\text{six} & 6 \\
\hline
\end{tabular}
\][/tex]

A. [tex]2c-6[/tex]; when [tex]c=7[/tex], the value is 8.

B. [tex]c^2-6[/tex]; when [tex]c=7[/tex], the value is 8.

C. [tex]c^2-6[/tex]; when [tex]c=7[/tex], the value is 43.

D. [tex]2c+6[/tex]; when [tex]c=7[/tex], the value is 20.



Answer :

Let's carefully break down and evaluate the expression as described in the problem step-by-step:

1. Identify the mathematical expression:
- Key words: "a number squared decreased by six."
- Using the provided replacements: "a number" with [tex]\( c \)[/tex], "squared" with exponent 2, and "decreased by" with minus (-).

2. Construct the expression:
- This translates to [tex]\( c^2 - 6 \)[/tex].

3. Evaluate the expression when [tex]\( c = 7 \)[/tex]:
- Substitute [tex]\( c \)[/tex] with 7.
- Calculate [tex]\( 7^2 - 6 \)[/tex].

4. Perform the calculation:
- [tex]\( 7^2 = 49 \)[/tex]
- Then, [tex]\( 49 - 6 = 43 \)[/tex].

Therefore, the correct expression and value when [tex]\( c = 7 \)[/tex] is:
[tex]\[ c^2 - 6; \text{ when } c=7, \text{ the value is } 43. \][/tex]

So, the correct answer is:
[tex]\[ c^2 - 6; \text{ when } c=7, \text{ the value is } 43. \][/tex]