MKMathematics Knowledge

Exponents & Polynomials

Exponents are shorthand for repeated multiplication — learn the six rules and ASVAB polynomial questions become mechanical.

Formula Reference

  • Product rule: xᵃ × xᵇ = xᵃ⁺ᵇ (same base, add exponents)
  • Quotient rule: xᵃ ÷ xᵇ = xᵃ⁻ᵇ (same base, subtract exponents)
  • Power rule: (xᵃ)ᵇ = xᵃˣᵇ (exponent of an exponent — multiply)
  • Zero exponent: x⁰ = 1 for any nonzero x
  • Negative exponent: x⁻ᵃ = 1/xᵃ
  • Distributing exponents: (xy)ᵃ = xᵃ × yᵃ — exponents apply to every factor inside

What the ASVAB is actually testing

Exponent questions on MK test whether you know the rules for combining powers — product rule, quotient rule, power rule, zero and negative exponents. Polynomial questions test whether you can expand or factor simple expressions. The test stays at the level of two-term polynomials (binomials) and clean integer exponents.

Nothing here is exotic. It's rule application.

The six exponent rules

Think of exponents as counting how many times a base is multiplied. That perspective makes the rules obvious:

  • Product rule: x² × x³ = (x×x)(x×x×x) = x⁵ — count up the multiplications, add the exponents.
  • Quotient rule: x⁵ ÷ x² = x³ — cancel pairs, subtract exponents.
  • Power rule: (x²)³ = x²×x²×x² = x⁶ — multiply exponents.
  • Zero exponent: Any nonzero base raised to 0 equals 1. This is a definition, not a coincidence.
  • Negative exponent: x⁻² means 1/x² — it's a reciprocal, not a negative number.
  • Distributing over multiplication: (2x)³ = 2³ × x³ = 8x³. The exponent applies to every factor.

The FOIL trap

The most missed polynomial question: (x + a)² = x² + 2ax + a², NOT x² + a². The middle term (2ax) comes from the outer and inner products in FOIL. Skipping it is the most common binomial error on the ASVAB.

Write out all four FOIL products explicitly until the pattern is automatic.

Connection to other topics

Exponents appear inside geometry formulas (area = s² for a square, volume = s³ for a cube) and in algebraic expressions throughout MK. Polynomial expansion is needed whenever a problem gives you a factored form and asks for the expanded result or a specific value.

Common Pitfalls

  • Adding bases instead of exponents: x² × x³ ≠ x⁶ — it's x⁵
  • Applying exponent rules across unlike bases: x² × y³ cannot be simplified further
  • Thinking x⁰ = 0 — it equals 1 (for any nonzero x)
  • Mishandling negative exponents: 2⁻³ is 1/8, not −8
  • Distributing an exponent into addition: (x + y)² ≠ x² + y² — you must FOIL

Worked Examples

Q1: Simplify: x⁴ × x³

Answer: Same base, add exponents: x⁴⁺³ = x⁷

Q2: Simplify: (2x²)³

Answer: Apply power rule to each factor: 2³ × x²ˣ³ = 8x⁶

Q3: What is 5⁰?

Answer: Any nonzero number to the zero power equals 1. Answer: 1

Q4: Expand: (x + 3)(x − 2)

Answer: FOIL: First: x², Outer: −2x, Inner: 3x, Last: −6. Combine: x² + x − 6

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