Which shows how to find the value of this expression when [tex]\( x=-2 \)[/tex] and [tex]\( y=5 \)[/tex] ?

[tex]\[
\left(3 x^3 y^{-2}\right)^2
\][/tex]

A. [tex]\(\frac{3^2(-2)^6}{5^4}\)[/tex]

B. [tex]\(\frac{3(-2)^6}{5^4}\)[/tex]

C. [tex]\(\frac{3^2(5)^6}{(-2)^4}\)[/tex]

D. [tex]\(\frac{3}{(2)^6 5^4}\)[/tex]



Answer :

Certainly! Let's break down the provided expressions to see which one correctly computes the value of the given expression [tex]\(\left(3 x^3 y^{-2}\right)^2\)[/tex] when [tex]\(x = -2\)[/tex] and [tex]\(y = 5\)[/tex].

First, let's start with the expression:
[tex]\[ \left(3 x^3 y^{-2}\right)^2 \][/tex]

We'll substitute [tex]\(x = -2\)[/tex] and [tex]\(y = 5\)[/tex]:
[tex]\[ \left(3 (-2)^3 5^{-2}\right)^2 \][/tex]

Calculate each part inside the parentheses:
1. [tex]\( (-2)^3 = -8 \)[/tex]
2. [tex]\( 5^{-2} = \frac{1}{5^2} = \frac{1}{25} \)[/tex]

Now, substituting these values into the expression:
[tex]\[ \left(3 \cdot (-8) \cdot \frac{1}{25}\right)^2 \][/tex]
[tex]\[ \left(\frac{3 \cdot (-8)}{25}\right)^2 \][/tex]
[tex]\[ \left(\frac{-24}{25}\right)^2 \][/tex]

Now, square the fraction:
[tex]\[ \left(\frac{-24}{25}\right)^2 = \frac{(-24)^2}{25^2} \][/tex]
[tex]\[ = \frac{576}{625} \][/tex]

This is the simplified form of the original expression. The closest matching option to this simplified form should be verified to see if it equals our simplified result of [tex]\(\frac{576}{625}\)[/tex].

Let's evaluate the given options:

1. [tex]\(\frac{3^2 \cdot (-2)^6}{5^4}\)[/tex]:
[tex]\[ = \frac{9 \cdot 64}{625} = \frac{576}{625} \][/tex]

2. [tex]\(\frac{3 \cdot (-2)^6}{5^4}\)[/tex]:
[tex]\[ = \frac{3 \cdot 64}{625} = \frac{192}{625} \][/tex]

3. [tex]\(\frac{3^2 \cdot 5^6}{(-2)^4}\)[/tex]:
[tex]\[ = \frac{9 \cdot 15625}{16} = 8789.0625 \][/tex]

4. [tex]\(\frac{3}{(2^6 \cdot 5^4)}\)[/tex]:
[tex]\[ = \frac{3}{4096 \cdot 625} = \frac{3}{2560000} = 7.5 \times 10^{-5} \][/tex]

From these calculations, we can see that the correct expression that matches our original calculation, [tex]\(\frac{576}{625}\)[/tex], is:
[tex]\[ \boxed{\frac{3^2(-2)^6}{5^4}} \][/tex]