The problem asks whether Neil made a mistake in simplifying the expression $\frac{5^{-6}}{5^{-4}}$. The steps Neil took are: Step 1: $\frac{5^{-6}}{5^{-4}} = 5^{-6-(-4)}$ Step 2: $5^{-6-(-4)} = 5^{-2}$ Step 3: $5^{-2} = \frac{1}{5^2}$

AlgebraExponentsSimplificationAlgebraic Manipulation
2025/3/14

1. Problem Description

The problem asks whether Neil made a mistake in simplifying the expression 5654\frac{5^{-6}}{5^{-4}}. The steps Neil took are:
Step 1: 5654=56(4)\frac{5^{-6}}{5^{-4}} = 5^{-6-(-4)}
Step 2: 56(4)=525^{-6-(-4)} = 5^{-2}
Step 3: 52=1525^{-2} = \frac{1}{5^2}

2. Solution Steps

To determine if Neil made a mistake, we need to simplify the original expression correctly and compare it to Neil's steps.
The rule for dividing exponents with the same base is:
aman=amn\frac{a^m}{a^n} = a^{m-n}
Applying this rule to the expression:
5654=56(4)\frac{5^{-6}}{5^{-4}} = 5^{-6 - (-4)}
Step 1: 56(4)=56+4=525^{-6 - (-4)} = 5^{-6 + 4} = 5^{-2}.
So far, Neil is correct.
Step 2: Neil states 56(4)=525^{-6-(-4)} = 5^{-2}.
6(4)=6+4=2-6-(-4) = -6+4 = -2. This is also correct.
Step 3: Neil states 52=1525^{-2} = \frac{1}{5^2}.
We know that an=1ana^{-n} = \frac{1}{a^n}. Therefore 52=1525^{-2} = \frac{1}{5^2}. This is also correct.
Since all the steps are correct, Neil did not make a mistake.

3. Final Answer

Neil did not make a mistake.