Rearranging to solve an equation (quick question)

[Yaaaldi]

Homework Statement

Say I had x = y-2 / y + 3

How would I go about rearranging for y= ?

I can't think how to simplify it down to a single y term.

 

[spamiam]

If you don't know how to start, just trying playing around with it. My first step would be to get rid of the y+3 in the denominator.

 

[bigfooted]

Multiply all terms by y.
You then have a second degree polynomial in y, which can be solved in the usual manner (assuming y does not depend on x).

 

[spamiam]

Multiply all terms by y.
You then have a second degree polynomial in y, which can be solved in the usual manner (assuming y does not depend on x).

This seems unnecessary to me. One can solve this simply by multiplying and factoring.

 

[Mark44]

Homework Statement

Say I had x = y-2 / y + 3

I'm assuming you mean x = (y - 2)/(y + 3). What you wrote is actually x = y - (2/y) + 3.

The lesson is: USE PARENTHESES!

 

[rollcast]

I'm assuming you mean x = (y - 2)/(y + 3). What you wrote is actually x = y - (2/y) + 3.

The lesson is: USE PARENTHESES!

Or use LATEX.

 

[eumyang]

Multiply all terms by y.
You then have a second degree polynomial in y, which can be solved in the usual manner (assuming y does not depend on x).

This seems unnecessary to me. One can solve this simply by multiplying and factoring.

I'm assuming that bigfooted read the problem as x = y - (2/y) + 3. If it is supposed to be x = (y - 2)/(y + 3) then of course multiplying and factoring would be the way to go.