Skill: Apply the product rule for powers

Explanation and Free Practice Resources

For powers with the same base, multiplying ama^m by ana^n combines the repeated factors, giving am+na^{m+n}; the exponent records the total number of factors of aa, rather than being multiplied. This rule applies to numerical or algebraic expressions with whole-number exponents and supports efficient computation and scientific notation, while unlike bases and extensions to negative or fractional exponents are not included.

Detailed Explanation: Apply the product rule for powers

When multiplying powers with the same base, keep the base and add the exponents:

am⋅an=am+na^m \cdot a^n=a^{m+n}

The exponents are added because they count the total number of factors of aa.

Example

Simplify:

23⋅242^3\cdot 2^4

Step 1: Check the bases.
Both powers have base 22, so the product rule applies.

Step 2: Add the exponents.

23⋅24=23+42^3\cdot 2^4=2^{3+4}

Step 3: Simplify the exponent.

23+4=272^{3+4}=2^7

So,

23⋅24=27\boxed{2^3\cdot 2^4=2^7}

The exponents are added, not multiplied, because there are 3+4=73+4=7 total factors of 22:

(2⋅2⋅2)(2⋅2⋅2⋅2)=27(2\cdot2\cdot2)(2\cdot2\cdot2\cdot2)=2^7

Learn by doing: Apply the product rule for powers

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Exponents - Multiplication - Positive by Positive to Positive


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