Higher Maths help - '00 algebra q2. part c)

Funkstard

It's a bitch of a factorising question, and it happens to be the only year I've lost my teachers notes for!

Part i) is fine, you have to factorise a*4-b*4 (a*4 = a to the power of 4)

Now part ii) is a*5 - a*5b - a(b*4) + b*5. If that even makes sense.

Any help anyone?

Diamondmaker

stick to the rugby:D

Shanegggg

a*5 - a*5b - a(b*4) + b*5
= a*4(a-b)-b*4(a-b)
= (a-b)(a*4-b*4)
= (a-b)(a-b)(a+b)(a*2+b*2)

(a+b)(a*2+b*2)(a-b)*2

Thats the answer there. Good luck!

Funkstard

Ahh right cheers. I was trying to do it like (a*5 + b*5) - ab(a*4 - b*4), and the power to 5 was screwing me over. Even thought of bringing the binomial into it but quickly realised I was doing something wrong!

Kwekubo

Just remember that, within a question part, part i usually leads on to part ii and so on like it does there.

Funkstard

Well my way had it leading on from part i) too with with ab(a*4 - b*4) thing. They haven't asked a part c) factorising question since then so maybe they've fallen out of favour

Gileadi

or that there due to come up again...