Exponents are a way to write repeated multiplication. Writing 5 x 5 x 5 x 5 x 5 x 5 takes a long time, so we write 56 instead. However, when we need to add, subtract, multiply, or divide these powers, things can get messy.
Thankfully, mathematics gives us a set of rules called the Laws of Exponents. These laws act as shortcuts. They allow us to simplify complex expressions without expanding huge numbers. Mastering these laws is essential for Algebra, Physics, and Engineering.
[Image of laws of exponents summary chart]1. The Product Rule
Rule: When you multiply two terms with the same base, you add the exponents.
Why?
23 x 22
= (2 x 2 x 2) x (2 x 2)
= 2 x 2 x 2 x 2 x 2
= 25
Note: The base must be the same. You cannot use this rule for 23 x 52.
2. The Quotient Rule
Rule: When you divide two terms with the same base, you subtract the exponents.
Example:
56 / 52 = 56-2 = 54.
3. Power of a Power Rule
Rule: When you raise an exponent to another power, you multiply the exponents.
Example: (32)3
This means 32 multiplied by itself 3 times.
32 x 32 x 32 = 32+2+2 = 36.
Shortcut: 2 x 3 = 6.
4. Power of a Product Rule
Rule: If a base is a product, the exponent applies to each factor inside.
Example: (2x)3 = 23 x x3 = 8x3.
Common Mistake: Writing this as 2x3. You must cube the 2 as well!
5. The Zero Exponent Rule
Rule: Any non-zero number raised to the power of zero is 1.
[Image of zero exponent pattern]Why? Look at the pattern of division.
52 / 52 = 25 / 25 = 1.
Using the Quotient Rule: 52-2 = 50.
Therefore, 50 must equal 1.
6. The Negative Exponent Rule
Rule: A negative exponent means reciprocal (1 divided by the number).
A negative exponent does NOT make the number negative. It tells you the number is on the wrong side of the fraction line.
Example:
2-3 = 1 / 23 = 1/8.
7. Conclusion
The Laws of Exponents transform difficult multiplication problems into simple addition problems. By understanding how to manipulate these powers, you can simplify equations that would otherwise fill entire pages. Whether you are dealing with the microscopic scale of atoms (10-10) or the astronomical scale of galaxies (1021), these laws keep the numbers under control.