1. **Stating the problem:** We want to find variables in a binomial equation, which typically looks like $ (a + b)^n $. 2. **Formula used:** The binomial theorem states: $$ (a + b)^n = \sum_{k=0}^n \binom{n}{k} a^{n-k} b^k $$ where $\binom{n}{k} = \frac{n!}{k!(n-k)!}$ is the binomial coefficient. 3. **Important rules:** - The exponent $n$ is a non-negative integer. - Each term in the expansion has the form $\binom{n}{k} a^{n-k} b^k$. - To find variables, identify $a$, $b$, and $n$ from the given expression. 4. **Example:** Suppose we have $ (x + 2)^3 $ and want to find variables and expand. 5. **Expansion:** Using the formula, $$ (x + 2)^3 = \binom{3}{0} x^3 2^0 + \binom{3}{1} x^2 2^1 + \binom{3}{2} x^1 2^2 + \binom{3}{3} x^0 2^3 $$ 6. **Calculate coefficients:** $$ = 1 \cdot x^3 \cdot 1 + 3 \cdot x^2 \cdot 2 + 3 \cdot x \cdot 4 + 1 \cdot 1 \cdot 8 $$ 7. **Simplify:** $$ = x^3 + 6x^2 + 12x + 8 $$ 8. **Summary:** To find variables in a binomial equation, identify $a$, $b$, and $n$ in $ (a + b)^n $, then use the binomial theorem to expand or analyze the expression.