The question asks to evaluate the function $f(x) = 2x + 1$ by substituting $x = 1$ to find $f(1)$.

Let's go through it step-by-step:

1. Start with the function: $f(x) = 2x + 1$

2. Substitute $x = 1$ to find $f(1)$: $f(1) = 2(1) + 1$

3. Calculate the expression: $f(1) = 2 + 1 = 3$

The correct choice that matches this setup is:

• f(1) = 2(1) + 1

This is the middle (green) option on the screen.

Would you like a further breakdown or have additional questions on this?

Here are five related questions to deepen understanding:

1. What would the function look like if you substituted $x = 2$ instead?
2. How do you interpret the value of $f(1) = 3$ in a real-world context if this function represents a scenario?
3. What would be the result if the function were $f(x) = 3x + 2$ and you substituted $x = 1$?
4. How do you determine if a function is linear, like $f(x) = 2x + 1$?
5. How would the function change if the constant were increased to 2, making it $f(x) = 2x + 2$?

Tip: When substituting values into a function, carefully replace only the variable, and keep the rest of the function's structure the same.