simplify this (1 Viewer)

[abdog]

(x^-1- 1)/x - 1

 

[onedaysnotice]

= x^-1 - 1/x - 1
= 1/x - 1/x - 1
= -1

 

[abdog]

LOL, I forgot the brackets! I've put them in now.

 

[abdog]

I still can't get it, the answer is -1/x

 

[Nws m8]

Are you serious ?

 

[Leffife]

The way you set out the question is just horrible!

Does it ask this?

 

[Leffife]

Actually, this is unusual the image didn't upload.

 

[lochnessmonsta]

Multiply top and bottom by x ---> (1-x)/x(x-1)
=-(x-1)/x(x-1)
=-1/x

 

[abdog]

Yeah, that's the question

 

[abdog]

Can you actually multiply stuff like that?

 

[Leffife]

Okay and YES you can multiply like that. He didn't change anything, just its appearance.

 

[lochnessmonsta]

I didnt change anything, if you look at it I'm multiplying by 1, in the form x/x

 

[abdog]

how do you know you have to multiply it by x?

 

[Leffife]

You just have to realise that multiplying this one by 'x' is probably the fastest method. You realise "x^-1" = "1/x". Then by realising this if you multiply the numerator and denominator by "x" you will remove the "1/x" to form "x" making it look neater... etc. Well that's pretty much why it's best to use this method.

 

[Nws m8]

how do you know you have to multiply it by x?

So we can get rid of stuff, that comes from practice ....

 

[thebaase]

Or you can do 1/x - 1 / x-1 = (1-x)/1 / x-1 = 1-x /x * 1/ x-1 = 1-x/(x^2-x) = 1-x/x(x-1) = 1-x/-x(1-x) = -1/x