Question

factorise 81 - a power 4 x power 2​

Answer 1

Step-by-step explanation:

81=9×9=9^2

9^2-a^4x^2

(9-a^2x)^2

Answer 2

Step-by-step explanation:

81-a⁴x²

=9²-(a²)²×x²

=(9)²-(a²x)²

applying identity a²-b²=a-b×a+b

=(9+a²x)(9-a²x)