25-9(2x-7)² factorisez
25 - 9(2x - 7)² = (5)² - (3)² × (2x - 7)²
= (5)² - (3 × (2x - 7))²
= (5)² - (6x - 21)²
= (5 + (6x - 21)) (5 - (6x - 21))
= (5 + 6x - 21) (5 - 6x + 21)
= (6x - 16) (-6x + 26)
