Let’s analyze the problem:

Problem Description:

The function $f$ is described with the following rule: a number $x$ is multiplied by $-3$, and then $8$ is added to the result.

a) Form the function expression.

The function can be written as: $f(x) = -3x + 8$

b) Calculate the function values $f(-2)$ and $f(5)$.

1. For $f(-2)$: $f(-2) = -3(-2) + 8 = 6 + 8 = 14$

2. For $f(5)$: $f(5) = -3(5) + 8 = -15 + 8 = -7$

Final Results:

• Function expression: $f(x) = -3x + 8$
• $f(-2) = 14$
• $f(5) = -7$

Would you like further clarifications?

Related Questions:

1. What is the graph of $f(x) = -3x + 8$?
2. How would you solve $f(x) = 0$?
3. What happens to $f(x)$ when $x$ increases by 1?
4. How does the function $f(x) = -3x + 8$ compare to $f(x) = 3x - 8$?
5. What are the intercepts of $f(x)$ with the axes?

Tip:

When creating functions from descriptions, carefully match each operation to the given rule to avoid errors!