1.

Factorise: 9a^2-(a^2 - 4)^2

Answer»

Answer:

9a^2 -(a^2 -4)^2

Remember?

A^2 -B^2 =(A+B)(A-B)

Therefore,

9a^2 -(a^2 -4)^2

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

=(3a +a^2 -4)(3a -a^2 +4)

= -(a^2 +3a -4)(a^2 -3a -4)

= -(a^2 +4A -a -4)(a^2 -4a +a -4)

= -(a+4)(a-1)(a-4)(a+1)

= -(a^2 -16)(a^2 -1)


Discussion

No Comment Found

Related InterviewSolutions