What is the following product? Assume [tex]x \geq 0[/tex].

[tex]\left(4x\sqrt{5x^2} + 2x^2\sqrt{6}\right)^2[/tex]

A. [tex]104x^4 + 8x^4\sqrt{30x}[/tex]

B. [tex]80x^6 + 8x^5 + 8x^5\sqrt{30} + 24x^4[/tex]

C. [tex]104x^6[/tex]

D. [tex]104x^4 + 16x^4\sqrt{30}[/tex]



Answer :

To determine which given product matches the expression [tex]\(\left(4 x \sqrt{5 x^2} + 2 x^2 \sqrt{6}\right)^2\)[/tex], we first need to simplify the expression step by step.

1. Simplify Inside the Parentheses:

Start with the expression inside the parentheses:

[tex]\[ 4 x \sqrt{5 x^2} + 2 x^2 \sqrt{6} \][/tex]

2. Simplify Each Term:

- For the first term [tex]\(4 x \sqrt{5 x^2}\)[/tex]:
[tex]\[ 4 x \sqrt{5 x^2} = 4 x \cdot \sqrt{5} \cdot \sqrt{x^2} = 4 x \cdot \sqrt{5} \cdot x = 4 x^2 \sqrt{5} \][/tex]

- For the second term [tex]\(2 x^2 \sqrt{6}\)[/tex]:
[tex]\[ 2 x^2 \sqrt{6} \][/tex]

Now the expression inside the parentheses is:
[tex]\[ 4 x^2 \sqrt{5} + 2 x^2 \sqrt{6} \][/tex]

3. Square the Entire Expression:

Square the simplified expression:
[tex]\[ \left(4 x^2 \sqrt{5} + 2 x^2 \sqrt{6}\right)^2 \][/tex]

Use the binomial expansion formula [tex]\((a + b)^2 = a^2 + 2ab + b^2\)[/tex] where [tex]\(a = 4 x^2 \sqrt{5}\)[/tex] and [tex]\(b = 2 x^2 \sqrt{6}\)[/tex]:

- Compute [tex]\(a^2\)[/tex]:
[tex]\[ a^2 = \left(4 x^2 \sqrt{5}\right)^2 = 16 x^4 \cdot 5 = 80 x^4 \][/tex]

- Compute [tex]\(b^2\)[/tex]:
[tex]\[ b^2 = \left(2 x^2 \sqrt{6}\right)^2 = 4 x^4 \cdot 6 = 24 x^4 \][/tex]

- Compute [tex]\(2ab\)[/tex]:
[tex]\[ 2ab = 2 \cdot \left(4 x^2 \sqrt{5}\right) \cdot \left(2 x^2 \sqrt{6}\right) = 2 \cdot 8 x^4 \cdot \sqrt{30} = 16 x^4 \sqrt{30} \][/tex]

Adding all these together gives:
[tex]\[ \left(4 x^2 \sqrt{5} + 2 x^2 \sqrt{6}\right)^2 = 80 x^4 + 24 x^4 + 16 x^4 \sqrt{30} \][/tex]
[tex]\[ = 104 x^4 + 16 x^4 \sqrt{30} \][/tex]

4. Identify the Correct Option:

Comparing with the given options, we see that the right match is:

[tex]\[ 104 x^4 + 16 x^4 \sqrt{30} \][/tex]

Therefore, the correct answer is:

[tex]\[ \boxed{104 x^4 + 16 x^4 \sqrt{30}} \][/tex]
Which corresponds to option 4.