Question

Pls answer the 84and85 question

Answer 1

answr 84. a^4-81=0

a^4=81

a^4=3^4

a=3

I hope it will help you

Answer 2

Answer:

84.(a+3)(a-3)( a^2+9)

85. 2n(2+n)(2-n)(4+n^2)

Step-by-step explanation:

Both the questions can be done using identity: (a^2)-(b^2)=(a+b)(a-b)

84. (a^4)-81

={(a^2)^2}-(9^2)

= {(a^2)-9}(a^2+9)

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

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

85. 32n-2n^5

=2n[16-n^4]

=2n[{4}^2-{n^2}^2]

=2n[4-n^2][4+n^2]

=2n[{2}^2-{n}^2][4+n^2]

=2n(2+n)(2-n)(4+n^2)