Problem 16 - Algebra 1

Question

Evaluate the expression for the given value of the variable. $$t^{5}-10 t \text { when } t=3$$

Step-by-Step Solution

Answer

The result of evaluating the expression \(t^{5}-10 t\) for \(t=3\) is 213.

Step 1 - Substitute the given value

Substitute \(t = 3\) into the equation \(t^{5}-10 t\). So, the equation becomes: \(3^{5}- 10*3\)

Step 2 - Apply the Power rule first

Calculate the power first, \(3^5 = 243\), So, the equation becomes: \(243 - 10*3\)

Step 3 - Perform Multiplication

Next, calculate the multiplication, \(10 * 3 = 30\), So, the expression becomes: \(243 - 30\)

Step 4 - Perform Subtraction

Finally, perform subtraction, \(243 - 30 = 213\)

Key Concepts

Powers and Exponents

Powers and exponents are essential tools in algebraic expressions that simplify repeated multiplication of the same number. When you see a term like \(t^5\), it means "\(t\) raised to the power of 5," or in other words, multiplying \(t\) by itself five times: \(t \times t \times t \times t \times t\). Using powers and exponents makes it easier to write and compute such expressions without having to write out each factor, saving time and reducing complexity.

In our exercise, \(3^5\) is equal to 243 because you multiply 3 by itself five times:\(3 \times 3 \times 3 \times 3 \times 3 = 243\). Understanding how to work with powers and exponents is crucial for many math problems, especially when dealing with polynomial expressions or scientific calculations.

Powers and exponents also follow specific rules. For example, multiplying powers with the same base means you add their exponents, and dividing powers with the same base means you subtract the exponents. Being familiar with these rules is key to manipulating algebraic expressions effectively.

Substitution Method

The substitution method in algebra refers to replacing a variable with a given numerical value to simplify or solve equations. This technique is very helpful, especially when you need to evaluate expressions for specific variable values.

In the example problem, we substitute \(t = 3\) into the expression \(t^5 - 10t\). By replacing the variable \(t\) with 3, the expression becomes \(3^5 - 10 \times 3\).

• This simplification makes it possible to calculate a precise numerical result.
• Substitution is a straightforward method that allows complex algebraic expressions to be reduced to basic arithmetic.

Remember that the substitution step is critical for many algebraic problems, especially when testing solutions or analyzing functions at specific points.

Order of Operations

The order of operations is a fundamental principle in mathematics that dictates the correct sequence to evaluate an expression. It helps in performing operations in a consistent manner, avoiding ambiguity. You may be familiar with the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division (left to right), Addition and Subtraction (left to right)), which summarizes these steps.

Applying the correct order of operations ensures accurate results.
In our problem:

• We perform any calculation with exponents first. Thus, we compute \(3^5 = 243\) before handling multiplication or subtraction.
• Next, we deal with multiplication: \(10 \times 3 = 30\).
• Finally, subtraction is performed: \(243 - 30 = 213\).

Understanding and applying the order of operations is crucial in mathematics, as it helps maintain the integrity of mathematical expressions and ensures everyone interprets expressions the same way. Without it, calculating expressions could lead to different outcomes.