MHB Is my factoring correct for these polynomials?

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The discussion focuses on the correct factoring of two polynomials: (A) u^2v^2 - 225 and (B) 81x^4 - x^2. For (A), the factorization is confirmed as (uv - 15)(uv + 15), which is correct. For (B), the initial factorization x^2(81x^2 - 1) is also correct, and it can be further factored into x^2(9x - 1)(9x + 1). Both problems illustrate the concept of factoring differences of perfect squares, affirming the accuracy of the solutions provided.
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Factor each polynomial given.

(A) u^2v^2 - 225

(B) 81x^4 - x^2

For (A), I got (uv - 15)(uv + 15). Is this right?

Solution for (B):

x^2(81x^2 - 1)

I think the binomial inside the parentheses can be factored.

So, (81x^2 - 1) becomes (9x - 1)(9x + 1).

My answer for (B) is x^2(9x - 1)(9x + 1).

Is this correct?
 
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Both are correct.
These are both problems testing your knowledge of factoring values that are "perfect squares".
Meaning,
a^2 - b^2 = (a+b)(a-b) For example,
in (a) you have u^2v^2 - 225. Using the formula, a=uv and b=15. So your answer is (a+b)(a-b)=(uv+15)(uv-15).
 
joypav said:
Both are correct.
These are both problems testing your knowledge of factoring values that are "perfect squares".

Not perfect squares but difference of perfect squares
 
It feels awesome to get the right answer.
 
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