explain how to factorise i,j and n

Answer:
see explanation
Step-by-step explanation:
A difference of squares is factored in general as
a² - b² = (a - b)(a + b)
(i)
(x + 5)² - 16 ← is a difference of squares, that is
(x + 5)² - 4²
= (x + 5 - 4)(x + 5 + 4)
= (x + 1)(x + 9)
(j)
(x - 4)² - 9 ← is a difference of squares, that is
(x - 4)² - 3²
= (x - 4 - 3)(x - 4 + 3)
= (x - 7)(x - 1)
(n)
(2y + 7)² - y² ← is a difference of squares
= (2y + 7 - y)(2y + 7 + y)
=(y + 7)(3y + 7)