(i) a⁴-b⁴ = (a²)²-(b²)²
= (a²-b²)(a²+b²) [∵ a²-b²-(a-b)(a+b)]
= (a-b)(a+b)(a²+b²) [∵ a²-b²-(a-b)(a+b)]
(ii) p⁴-81=(p²)²-(9²)²
= (9²-9)(9²+9) [∵ a²-b²-(a-b)(a+b)]
= (p²-3²)(p²+9)
= (p-3)(p+3)(p²+9) [∵ a²-b²-(a-b)(a+b)]

Class 8 Maths Chapter 11 Exercise 14.2 Solution in Video

for more answers vist to:
https://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-14/