Question

Hi boys can you help me pls!! Will mark brainliest!!!

Answer 1

Answer:

A

Step-by-step explanation:

Given

5x² - 45 ← factor out 5 from each term

= 5(x² - 9)

x² - 9 is a difference of squares and factors in general as

a² - b² = (a + b)(a - b), thus

x² - 9

= x² - 3² = (x + 3)(x - 3)

and

5x² - 45

= 5(x + 3)(x - 3) → A

Answer 2

Answer:

A.  5(x + 3)(x - 3)

Step-by-step explanation:

Given expression: $\[5x^{2}-45\]$

=  $\[5(x^{2}-9)\]$

=  $\[5(x^{2}-3^{2})\]$ -------------(1)

But  $\[(x^{2}-3^{2}) = (x+3)(x-3)\]$

Substituting in (1):

=  $\[5(x+3)(x-3)\]$

Among the given options, This corresponds to option A in the list.

Option B corresponds to  $\[5x^{2}-225\]$

Option C corresponds to  $\[5x^{2}-405\]$

Option D corresponds to  $\[5x^{2}-16x-45\]$