Question

Which equation is true?

9x2 – 25 = (3x – 5)(3x – 5)
9x2 – 25 = (3x – 5)(3x + 5)
9x2 – 25 = –(3x + 5)(3x + 5)
9x2 – 25 = –(3x + 5)(3x – 5)

Answer 1

9x2 – 25 = (3x – 5)(3x + 5)

Answer 2

Answer:

$(3x-5)(3x+5)$ is the right answer.

Step-by-step explanation:

The given expression is :

$9x^{2} -25$

We can say that it is in the form of $a^{2}- b^{2}$

$a^{2}$ is $9x^{2}$ or a = 3x

$b^{2}$ is 25 or b = 5

Now, when we multiply $(a-b)(a+b)$ we get $a^{2}- b^{2}$

So, putting the values of a and b in $(a-b)(a+b)$ to get the answer.

$(3x-5)(3x+5)$

We can check this by multiplying both, $9x^{2} +15x-15x-25$

= $9x^{2} -25$

Therefore, option B is correct.