We are given the expression:

$\frac{a^2 - 3c}{b}$

Substitute the values $a = 2$, $b = 3$, and $c = -1$:

1. First, calculate $a^2$: $a^2 = 2^2 = 4$

2. Now, calculate $3c$: $3c = 3 \times (-1) = -3$

3. Substitute these values into the expression: $\frac{a^2 - 3c}{b} = \frac{4 - (-3)}{3} = \frac{4 + 3}{3} = \frac{7}{3}$

So, the final result is:

$\frac{7}{3}$

Would you like more details or have any questions?

Here are 5 related questions to explore:

1. What is the result if $a = 4$, $b = 2$, and $c = -2$?
2. How would the result change if we added a term $d$ in the numerator?
3. Can you factor expressions similar to $a^2 - 3c$ easily?
4. What happens when you apply the same operation to a quadratic expression?
5. How does simplifying fractions like $\frac{7}{3}$ affect real-world applications?

Tip: Always simplify expressions step by step to avoid errors in algebraic manipulations.