To solve this we are going to use the difference of squares formula:[tex]a^2-b^2=(a+b)(a-b)[/tex].
Notice that the first term of our binomial [tex]9x^2[/tex] can be expressed as [tex](3x)^2[/tex]; similarly, the second term [tex]25[/tex] can be expressed as [tex]5^2[/tex]. So we can rewrite our binomial as follows:
[tex]9x^2-25=(3x)^2-5^2[/tex]
Now we have a difference of squares with [tex]a=3x[/tex] and [tex]b=5[/tex], so lets apply our formula:
[tex](3x)^2-5^2=(3x+5)(3x-5)[/tex]
We can conclude that the correct answer is A. (3x + 5)(3x − 5)
