Algebra · Lesson 13 of 13

Law of Exponents

Key rules and formulas, worked examples and 3 practice problems with step-by-step solutions.

Product Rule

Multiplying terms with the same base.

$$x^a \cdot x^b = x^{a+b}$$

Keep the base and add the exponents.

Example

Simplify:

$$x^4 \cdot x^5$$

Show solution
  • Step 1: Identify same base 'x'.
  • Step 2: Add exponents: $$4 + 5 = 9$$.
  • Step 3: Write result: $$x^9$$.

=> Conclusion: $$x^4 \cdot x^5 = x^9$$

Practice problems

  1. Problem 1

    Simplify:

    $$x^3 \cdot x^6$$

    Show solution

    Answer: $$x^9$$

    • Step 1: Keep base 'x'.
    • Step 2: Add exponents: $$3 + 6 = 9$$.

    => Conclusion: $$x^9$$.

    => Correct Option: B ($$x^9$$).

  2. Problem 2

    Simplify:

    $$(2x^4)(5x^3)$$

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    Answer: $$10x^7$$

    • Step 1: Multiply coefficients: $$2 \cdot 5 = 10$$.
    • Step 2: Apply Product Rule for variables: $$x^{4+3} = x^7$$.
    • Step 3: Combine: $$10x^7$$.

    => Conclusion: $$10x^7$$.

    => Correct Option: A ($$10x^7$$)

  3. Problem 3

    Simplify:

    $$(3x^2y^5)(4x^3y^2)$$

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    Answer: $$12x^5y^7$$

    • Step 1: Multiply coefficients: $$3 \cdot 4 = 12$$.
    • Step 2: Add exponents for x: $$x^{2+3} = x^5$$.
    • Step 3: Add exponents for y: $$y^{5+2} = y^7$$.
    • Step 4: Combine: $$12x^5y^7$$.

    => Conclusion: $$12x^5y^7$$.

    => Correct Option: B ($$12x^5y^7$$)