Why is this equation correct? (algebraic fraction simplification)

[Anarcho]

Homework Statement

Rearranging equation

Relevant Equations

z=((1+x)/(1+y)*a-a)/a)

Hi all,

I cannot figure out how I get to the alternate form. I really do need help here.

Not sure how this is done.
Thank you

 

[kuruman]

First you simplify the fraction by dividing numerator and denominator by $a$. Then you add the fraction to what's left in the numerator.

 

[Anarcho]

I have the same problem. But both wolframalpha as well as my notes get to the same conclussion. (scratching my head)

 

[DrClaude]

I have the same problem. But both wolframalpha as well as my notes get to the same conclussion. (scratching my head)

Have you tried it? Start by trying to simplify out the $a$.

 

[Mark44]

No, this is not what you get.

You're right. I'm going to delete my post. Bonehead mistake on my part...

 

[DrClaude]

You're right. I'm going to delete my post. Bonehead mistake on my part...

It happens even to the best of us

 

[Mark44]

I have the same problem. But both wolframalpha as well as my notes get to the same conclussion. (scratching my head)

I have deleted my earlier post, since my thinking was incorrect. Follow the hints given by @kuruman and @DrClaude.

 

[Anarcho]

Have you tried it? Start by trying to simplify out the aa.

I get $((x+1)/(y+1))−1$

 

[kuruman]

I get (x+1)/(y+1)-1

Simplify some more. Hint: $-1 = -\frac{y+1}{y+1}.$

 

[Anarcho]

And why is that? This might be the problem I don't understand it

 

[kuruman]

And why is that? This might be the problem I don't understand it

Are you saying you don't understand why a number divided by itself is equal to $1$?

 

[Anarcho]

I must look like an idot. Now I get it.

 

[kuruman]

I must look like an idot. Now I get it.

We all have our blind spots here and there.

 

[Chestermiller]

I get $((x+1)/(y+1))−1$

Have you ever heard the term "reducing to a common denominator?"