Question

x4-81 factorise it (Q1 to 30):​

Answer 1

Answer:

x^4-81

=(x^2)^2-(9)^2

=(x^2+9)(x^2-9)

=(x^2+9){(x)^2-(3)^2}

=(x^2+9)(x+3)(x-3)

Answer 2

Answer:

x^4-81

x^4-3^4

(x^2)^2-(3^2)^2

(a^2-b^2=(a-b) (a+b)

(x^2-3^2) (x^2+3^2)