Exponent rules

There are many properties and rules of exponents that can be used to simplify algebraic equations. Below are some of the most commonly used. Note that the terms "exponent" and "power" are often used interchangeably to refer to the superscripts in an expression. For example, in the term Qbn, Q is the coefficient, b is the base, and n is the exponent or power, as shown in the figure below.



Addition and subtraction

To add or subtract terms that contain exponents, the terms must have the same base and the same power. Otherwise, the terms cannot be added. If the base and power are the same, then the coefficients of the bases can be added or subtracted, while keeping the base and power the same. Given that P and Q are constant coefficients, this can be expressed as:

Examples

1. 3(32) + 32:

3(32) + 32 = (3 + 1)(32) = 4(32) = 36


2. 3x5 - 6x5:

3x5 - 6x5 = (3 - 6)x5 = -3x5

Multiplication

To multiply terms containing exponents, the terms must have the same base and/or the same power. To multiply terms with the same base, keep the same base and add the powers together. To multiply terms with different bases but the same power, raise the product of the bases to the power. This can be expressed as:

If the exponents have coefficients attached to their bases, multiply the coefficients together. Coefficients can be multiplied together even if the exponents have different bases.

Examples

1. 32 × 33:

32 × 33 = 32+3 = 35


2. 42 × 62:

42 × 62 = (4 × 6)2 = 242 = 576

If exponents have the same power and the same base, the expression can be simplified using either of the above rules:

3. 52 × 52:

52 × 52 = 52+2 = 54 = 625

OR

52 × 52 = (5 * 5)2 = 252 = 625

Division

To divide terms in an expression with exponents, the exponents must have the same base and/or the same power. To divide exponents that have the same base, keep the same base and subtract the power of the denominator from the power of the numerator. If the terms of an expression have the same power but different bases, divide the bases then raise the result to the power. If the exponents have coefficients attached to their bases, divide the coefficients. Coefficients can be divided even if the exponents have different bases.

Examples

1. :


2. :

If an exponent has a negative power, you still need to keep the same sign and subtract the power.

3. :

Negative exponents

A negative exponent just means to take the reciprocal of the base, then raise it to the positive positive power. This can be written as:

Example

Powers

When raising a power to another power, it is important to pay attention to order of operations. By convention:

This is different from (bn)m, where:

Examples

1. (43)2:

(43)2 = 43×2 = 46 = 4096

OR

(43)2 = 642 = 4096


2. 432:

432 = 4(32) = 49 = 262144