Evaluating exponent expressions with variables

TL;DR

Learn how to evaluate expressions with variables as bases and exponents using two examples.

Transcript

• [Instructor] We are asked to evaluate the expression five to the x power minus three to the x power for x equals two. So pause this video, and see if you can figure out, what does this expression equal when x equals two? All right, now let's work through this together. So what we want to do is everywhere we see an x, we want to replace it with a ... Read More

Key Insights

• 😑 In evaluating expressions with variables as bases and exponents, substitute the given values and simplify.
• 🪈 The order of operations dictates solving exponents before any other operation.
• 😑 Variables can be replaced with specific values to determine the result of an expression.

Questions & Answers

Q: How do you evaluate the expression 5^x - 3^x for x = 2?

By substituting x with 2, we get 5^2 - 3^2. Solving this, we get 25 - 9 which equals 16.

Q: What is the value of y^2 - x^4 when y = 9 and x = 2?

Substituting y with 9 and x with 2, we have 9^2 - 2^4. This simplifies to 81 - 16, resulting in 65.

Summary & Key Takeaways

• In the first example, the expression 5^x - 3^x is evaluated for x = 2, resulting in 16.

• The second example involves evaluating the expression y^2 - x^4 for y = 9 and x = 2, which equals 65.