The task in the image is to determine if a function is linear, and if it is, express it in the form $f(x) = ax + b$. If the function is not linear, you are instructed to write "NO LINEAL".

Given Functions:

1. The first function is $f(x) = 7 - 6x$.
2. The second function is $f(x) = \frac{-6}{x^2}$.

Analysis:

1. First Function: $f(x) = 7 - 6x$
   This is a linear function because it can be written in the form $f(x) = ax + b$, where $a = -6$ and $b = 7$. Hence, it is linear.

2. Second Function: $f(x) = \frac{-6}{x^2}$
   This function involves $x^2$ in the denominator, making it nonlinear. A linear function must have terms involving only $x$ (raised to the first power) or constants, which this function does not satisfy. Therefore, this function is not linear.

Conclusion:

• The first function $f(x) = 7 - 6x$ is linear and can be expressed in the form $f(x) = -6x + 7$.
• The second function $f(x) = \frac{-6}{x^2}$ is not linear (NO LINEAL).

Would you like further details or explanations? Here are some related questions you might want to explore:

1. What are the key properties of a linear function?
2. How do you differentiate between linear and nonlinear functions?
3. Can linear functions have more complex forms?
4. Why does the presence of $x^2$ make a function nonlinear?
5. How can we analyze a function's behavior graphically to identify linearity?

Tip: A function is linear if its graph is a straight line and if it can be expressed as $f(x) = ax + b$, where $a$ and $b$ are constants.