There are several formulas and equations that you should consider memorizing for the exam. These formulas are commonly used in various subjects and can greatly aid your problem-solving abilities. Here are some key formulas and equations categorized by subject:

Mathematics:
- Quadratic Formula: (-b ± √(b² - 4ac)) / (2a)
- Pythagorean Theorem: a² + b² = c²
- Distance Formula: √((x₂ - x₁)² + (y₂ - y₁)²)
- Slope of a Line: m = (y₂ - y₁) / (x₂ - x₁)
- Area of a Circle: A = πr²
- Volume of a Sphere: V = (4/3)πr³
- Sum of an Arithmetic Series: Sn = (n/2)(2a + (n-1)d)

Physics:
- Newton's Second Law of Motion: F = ma
- Law of Universal Gravitation: F = G(m₁m₂/r²)
- Ohm's Law: V = IR
- Kinetic Energy: KE = (1/2)mv²
- Work-Energy Theorem: W = ΔKE
- Snell's Law: n₁sinθ₁ = n₂sinθ₂

Chemistry:
- Ideal Gas Law: PV = nRT
- Henderson-Hasselbalch Equation: pH = pKa + log([A-]/[HA])
- Nernst Equation: Ecell = E°cell - (0.0592/n)log(Q)
- Rate Law: rate = k[A]x[B]y
- Avogadro's Law: V₁/n₁ = V₂/n₂

Biology:
- Hardy-Weinberg Equilibrium: p² + 2pq + q² = 1
- Photosynthesis Equation: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
- Krebs Cycle: Acetyl CoA + 3NAD⁺ + FAD + GDP + Pᵢ + 2H₂O → 3NADH + FADH₂ + GTP + CoA-SH + 2CO₂

These are just a few examples, and the specific formulas and equations you should memorize may vary depending on the syllabus or curriculum of your exam. It is important to review your study materials and identify the key formulas and equations that are relevant to your exam.

Remember, understanding the concepts behind these formulas and equations is equally important as memorizing them. Practice applying these formulas to solve problems and ensure that you comprehend the underlying principles.