Question

Divide and simplify. $$x^{7} \text { by } x^{4}$$

Short answer

\( x^3 \)

Step-by-step solution

Understand the laws of exponents for division

When dividing exponential expressions with the same base, you subtract the exponents according to the law \( a^{m} \div a^{n} = a^{m-n} \) where \( a \) is the base and \( m \) and \( n \) are the exponents.

Apply the exponent law to the problem

Use the law of exponents to divide \(x^{7} \) by \(x^{4} \) which is \(x^{7-4}\)

Subtract the exponents

Subtract the exponents to get \( x^{7-4} = x^{3} \)

Key concepts

Exponential Expressions

Exponential expressions are a shorthand way to express repeated multiplication of the same number. For instance, when we write \(2^5\), it indicates that the number 2 is multiplied by itself 5 times (\(2 \times 2 \times 2 \times 2 \times 2\)). In this notation, the base (2 in \(2^5\)) is the number being multiplied, and the exponent (5 in \(2^5\)) reflects how many times it is used in the multiplication.

Understanding how to interpret exponential expressions is crucial as it forms the basis of many mathematical and scientific calculations. These notations are not just limited to whole numbers. For example, \(x^n\) represents \(x\) multiplied by itself \(n\) number of times, where \(n\) can be any integer, rational number, or even an irrational number.

Simplifying Exponents

Simplifying exponents is a process that makes exponential expressions easier to understand and work with. To do this, we can use several laws of exponents. For example, when multiplying like bases, we add the exponents \(a^m \times a^n = a^{m+n}\). Conversely, when calculating a power of a power, we multiply the exponents \( (a^m)^n = a^{mn} \).

Additionally, when an exponent is zero, the value is always 1, \(a^0 = 1\) (provided \(a \eq 0\)), and negative exponents indicate a reciprocal \(a^{-n} = \frac{1}{a^n}\). Keeping these rules in mind, we can simplify complicated exponential expressions by applying these rules step by step, ensuring the expression is in its simplest form for easy calculation or comparison.

Dividing Exponents

Dividing exponents with the same base is another key concept within the laws of exponents. As shown in the step-by-step solution for \( x^7 \) divided by \( x^4 \), according to the laws of exponents, we subtract the exponent of the denominator from that of the numerator: \( \frac{a^m}{a^n} = a^{m-n} \). This particular rule streamlines calculations and simplifies expressions considerably.

Once you subtract the exponents, the result is the base raised to the difference of the two exponents. In our example, the expression simplifies to \( x^{7-4} = x^3 \), which indicates \( x \) multiplied by itself three times. It's important to remember that this rule only applies when the base numbers are the same because it leverages the fundamental principle that each division by a base is equivalent to removing one instance of that base from the multiplication.