To find: value of n

We know,

So, according to question:

⇒ (n + 5) (n + 4) = 22 (n – 1)

⇒ n² + 4n + 5n + 20 = 22n – 22

⇒ n² + 9n + 20 - 22n + 22 = 0

⇒ n² – 13n + 42 = 0

⇒ n² – 6n – 7n + 42 = 0

⇒ n(n – 6) – 7(n – 6) = 0

⇒ (n – 7) (n – 6) = 0

⇒ n = 7 or 6

∴ The value of n can either be 6 or 7