Question

Factor completely 25x2 − 9

(5x − 3)(5x − 3)

(5x + 3)(5x − 3)

(5x + 1)(5x − 9)

(5x − 1)(5x − 9)

Answer 1

If the question is 25xsquare -9
then answer will be
(5x+3)(5x-3)

Answer 2

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

Explanation:

Factor completely
`25x^2 - 9`

To factor this we write the numbers in square form

25 = 5*5= 5^2

9 = 3*3= 3^2

`5^2x^2 - 3^2`

`(5x)^2 - 3^2`

We apply difference of squares formula

a^2 - b^2 = (a+b)(a-b)

`(5x)^2 - 3^2`

a= 5 and b = 3

So it becomes, replace the numbers in the formula

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