Associated Topics || Dr. Math Home || Search Dr. Math

Turning an Equation Upside-Down

```
Date: 07/09/2001 at 21:31:17
From: Judy Fontenot
Subject: Turning an equation upside down

I am trying to help a neighbor. There is an example in the book that
I do not understand. After this step:

2/h = (a + b)/ab,

the book shows this:

h/2 = (ab)/(a + b).

Can you simply invert the fractions and maintain the equivalency? Or
is there something you do to both sides to accomplish this?

```

```
Date: 07/09/2001 at 23:30:16
From: Doctor Peterson
Subject: Re: Turning an equation upside down

Hi, Judy.

Yes, as long as you know that the values are non-zero, you can take
the reciprocal of both sides of an equation to get an equivalent
equation. This is just a shortcut for the following:

A = B                given
A / (AB) = B / (AB)  dividing by AB
1/B = 1/A            simplifying

As long as A and B are non-zero, this is all legal.

- Doctor Peterson, The Math Forum
http://mathforum.org/dr.math/
```
Associated Topics:
Middle School Algebra
Middle School Equations

Search the Dr. Math Library:

 Find items containing (put spaces between keywords):   Click only once for faster results: [ Choose "whole words" when searching for a word like age.] all keywords, in any order at least one, that exact phrase parts of words whole words

Submit your own question to Dr. Math
Math Forum Home || Math Library || Quick Reference || Math Forum Search