A4-b4=(a-b)(a+b)(a2+b2)?

I’m assuming you’re asking for the proof here.

Since you’ve used a4 to represent a^4, I’m going to use that too.

Let a2= X; b2= Y

Now, a4-b4= X2-Y2

= (X + Y) (X - Y)

=(a2 + b2) (a2- b2)

=(a2 + b2) (a + b) (a - b)

=(a + b) (a - b) (a2 + b2)

Hence, proved.

Hope that helped!

Step-by-step explanation: