Tyler simplified the expression [tex][tex]$x^{-3} y^{-9}$[/tex][/tex]. His procedure is shown below.
[tex][tex]$x^{-3} y^{-9} = \frac{1}{x^3} \cdot \frac{1}{y^{-9}} = \frac{1}{x^3 y^{-9}}$[/tex][/tex]

What is Tyler's error?

A. Both powers should be in the numerator with positive exponents.
B. Both powers should be in the denominator with positive exponents.
C. The power [tex][tex]$x^3$[/tex][/tex] should be in the numerator and the power [tex][tex]$y^9$[/tex][/tex] in the denominator.
D. The power [tex][tex]$y^9$[/tex][/tex] should be in the numerator and the power [tex][tex]$x^3$[/tex][/tex] in the denominator.



Answer :

Let's go through the detailed, step-by-step solution to identify Tyler's error and correctly simplify the expression [tex]\( x^{-3} y^{-9} \)[/tex].

1. Original Expression:
[tex]\[ x^{-3} y^{-9} \][/tex]

2. Applying the Property of Negative Exponents:
Recall that for any non-zero number [tex]\( a \)[/tex] and an integer [tex]\( n \)[/tex]:
[tex]\[ a^{-n} = \frac{1}{a^n} \][/tex]
Using this property on [tex]\( x^{-3} \)[/tex] and [tex]\( y^{-9} \)[/tex], we get:
[tex]\[ x^{-3} = \frac{1}{x^3} \][/tex]
[tex]\[ y^{-9} = \frac{1}{y^9} \][/tex]

3. Simplifying the Expression:
Substitute the simplified forms back into the original expression:
[tex]\[ x^{-3} y^{-9} = \frac{1}{x^3} \cdot \frac{1}{y^9} \][/tex]

4. Combining the Fractions:
Using the property of fractions [tex]\(\frac{a}{b} \cdot \frac{c}{d} = \frac{a \cdot c}{b \cdot d}\)[/tex], we can combine the fractions:
[tex]\[ \frac{1}{x^3} \cdot \frac{1}{y^9} = \frac{1 \cdot 1}{x^3 \cdot y^9} = \frac{1}{x^3 y^9} \][/tex]

5. Final Simplified Expression:
[tex]\[ x^{-3} y^{-9} = \frac{1}{x^3 y^9} \][/tex]

6. Identifying Tyler's Error:
Tyler's simplification steps were:
[tex]\[ x^{-3} y^{-9} \rightarrow \frac{1}{x^3} \cdot \frac{1}{y^{-9}} = \frac{1}{x^3 y^{-9}} \][/tex]
The mistake here is in not correctly applying the property of negative exponents to [tex]\( y^{-9} \)[/tex]. The [tex]\( y^{-9} \)[/tex] term should be in the denominator, with a positive exponent.

Therefore, the correct version should be:
[tex]\[ \frac{1}{x^3} \cdot \frac{1}{y^9} = \frac{1}{x^3 y^9} \][/tex]

Correct Answer:
The power [tex]\( y^9 \)[/tex] should be in the numerator and the power [tex]\( x^3 \)[/tex] in the denominator.

Therefore, the correct identification of Tyler's error is:

"The power [tex]\( y^9 \)[/tex] should be in the numerator and the power [tex]\( x^3 \)[/tex] in the denominator."