Factorise : 25 - (4x2 + 12x + 9). My answer is coming (8 + 2x)(2 - 2x), but in my book, its written
4(x + 4)(1-x). Plz help!
25 – (4x2 + 12x + 9)
= 25 – 4x2 – 12x – 9)
= 16 – 4x2 – 12x
= 4 (4 – x2 – 3x)
= 4 ( – x2 – 3x + 4)
= 4 ( – x2 – 4x + x + 4)
= 4 { – x (x + 4) + 1 (x + 4) }
= 4 (x + 4) (1 – x)