Select the correct answer.

Which expression is equivalent to [tex]$4 x^2 \sqrt{5 x^4} \cdot 3 \sqrt{5 x^8}$[/tex], if [tex]$x \neq 0$[/tex]?

A. [tex]$12 x^{10} \sqrt{5}$[/tex]
B. [tex][tex]$60 x^8$[/tex][/tex]
C. [tex]$35 x^{18}$[/tex]
D. [tex]$7 x^{10} \sqrt{5}$[/tex]



Answer :

Sure, let's analyze the given expression step-by-step to simplify and find the equivalent expression.

Given expression:
[tex]\[ 4 x^2 \sqrt{5 x^4} \cdot 3 \sqrt{5 x^8} \][/tex]

First, let's rewrite the square root terms for better simplification:

[tex]\[ \sqrt{5 x^4} \text{ and } \sqrt{5 x^8} \][/tex]

Since [tex]\( \sqrt{a \cdot b} = \sqrt{a} \cdot \sqrt{b} \)[/tex], we can rewrite them as:

[tex]\[ \sqrt{5 x^4} = \sqrt{5} \cdot \sqrt{x^4} = \sqrt{5} \cdot x^2 \][/tex]
[tex]\[ \sqrt{5 x^8} = \sqrt{5} \cdot \sqrt{x^8} = \sqrt{5} \cdot x^4 \][/tex]

Now, substitute these back into the original expression:

[tex]\[ 4 x^2 \cdot (\sqrt{5} \cdot x^2) \cdot 3 \cdot (\sqrt{5} \cdot x^4) \][/tex]

Combine the constants and the square root terms:

[tex]\[ 4 \cdot 3 \cdot x^2 \cdot x^2 \cdot x^4 \cdot \sqrt{5} \cdot \sqrt{5} \][/tex]

Since [tex]\( \sqrt{5} \cdot \sqrt{5} = 5 \)[/tex]:

[tex]\[ 4 \cdot 3 \cdot 5 \cdot x^2 \cdot x^2 \cdot x^4 \][/tex]

Simplify the constants:

[tex]\[ 4 \cdot 3 \cdot 5 = 60 \][/tex]

Combine the powers of [tex]\( x \)[/tex]:

[tex]\[ x^2 \cdot x^2 \cdot x^4 = x^{2+2+4} = x^8 \][/tex]

Thus, the expression simplifies to:

[tex]\[ 60 x^8 \][/tex]

Therefore, the correct answer is:

[tex]\[ \boxed{60 x^8} \][/tex]