1. **Problem a:** Find the missing value in the equation $a - 25 = 36$. 2. To solve for $a$, use the formula for solving linear equations: if $x - b = c$, then $x = c + b$. 3. Substitute the known values: $$a = 36 + 25$$ 4. Calculate the sum: $$a = 61$$ 5. **Problem c:** Find the missing value in $4 \times \square = 96$. 6. Use the formula for division to isolate the missing value: if $a \times x = b$, then $x = \frac{b}{a}$. 7. Substitute the known values: $$\square = \frac{96}{4}$$ 8. Simplify the fraction: $$\square = \frac{\cancel{96}}{\cancel{4}} = 24$$ 9. **Problem e:** Find the missing value in $(5 \times \square) + 29 = 129$. 10. First, isolate the multiplication term: $$5 \times \square = 129 - 29$$ 11. Calculate the subtraction: $$5 \times \square = 100$$ 12. Now solve for $\square$: $$\square = \frac{100}{5}$$ 13. Simplify the fraction: $$\square = \frac{\cancel{100}}{\cancel{5}} = 20$$ 14. **Problem 2a:** Find the missing value in the addition problem: $$\begin{array}{c} 4 \\ + \square \end{array}$$ 15. Since the problem does not specify the sum, we cannot solve for the missing value without additional information. **Final answers:** - a: $61$ - c: $24$ - e: $20$ - 2a: Insufficient information to solve.