help with factorising (1 Viewer)

[crammy90]

partway through a question they get:
(e^ln2)^-2/3 + (e^ln2)^1/3
= 2^-2/3 + 2^1/3
= 2^2/3 x (2+1) <----how do they get this factorisation or whatever they did?
= 3*2^(2/3)

 

[PC]

No idea.

I'm not sure how you went from the question to the next line - unless 2^1/3 is a typo.

 

[crammy90]

No idea.

I'm not sure how you went from the question to the next line - unless 2^1/3 is a typo.

i had half sorry its fixed now

 

[tacogym27101990]

its an error it should be 3*2^(-2/3)

 

[crammy90]

its an error it should be 3*2^(-2/3)

i changed it once again lol :S
i didnt know how to represent it on computer
but the main point i dont understand is how they get from the second line and factorise to get
2^2/3 x (2+1)

 

[tacogym27101990]

so they have 2^(-2/3) + 2^1/3
so they take a common factor of 2^(-2/3) out
and to get 2^1/3 into that form, you have to change it into 2 X 2(-2/3) because thats like 2/2^(2/3)
so then taking that common factor out
you get 2^(-2/3)X(1+2)
=3X2^(-2/3)

 

[crammy90]

alrite kool i got it after a while. I think because u do 4unit u left out a few steps thinking id see them aha
but all is well now
i did:
2^(-2/3) + 2^1/3
= 1/(2^2/3) + 2^1/3
(cross multiplied)
= (1+2)/2^2/3
= 3 x 2^(-2/3)