The temperature on a summer afternoon is [tex]76^{\circ} F[/tex]. Define a variable and write an expression to find the temperature after it changes. Then evaluate your expression for a decrease of 8 degrees Fahrenheit.

A. [tex]76 - c[/tex]; when [tex]c = 8[/tex], [tex]76 - 8 = 68^{\circ} F[/tex]

B. [tex]76 + c[/tex]; when [tex]c = -8[/tex], [tex]76 + (-8) = 68^{\circ} F[/tex]

C. [tex]8 - c[/tex]; when [tex]c = 76[/tex], [tex]8 - 76 = -68^{\circ} F[/tex]

D. [tex]8 + c[/tex]; when [tex]c = -76[/tex], [tex]8 + (-76) = -68^{\circ} F[/tex]

To solve the problem of finding the new temperature after a decrease from the initial temperature, follow these steps:

1. Define a Variable: Let's call the change in temperature "c". If the temperature decreases, "c" will be a negative number.

2. Write an Expression: To account for changes in temperature, you can use the expression [tex]$76 + c$[/tex], where 76 degrees Fahrenheit is the initial temperature, and [tex]$c$[/tex] represents the change in temperature.

3. Evaluate the Expression: Since we are dealing with a decrease of 8 degrees, we set [tex]$c = -8$[/tex].

- Substitute [tex]$c = -8$[/tex] into the expression:
[tex]\[
76 + c = 76 + (-8)
\][/tex]

4. Calculate the Result:
- Simplify the expression:
[tex]\[
76 + (-8) = 76 - 8 = 68
\][/tex]

Therefore, after a decrease of 8 degrees Fahrenheit, the new temperature is [tex]$68^\circ F$[/tex].

The correct choice from the given options is:
- [tex]$76+c ; 76+(-8)=68 ; 68^{\circ} F$[/tex]