<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Our Terms of Use (click here to view) have changed. By continuing to use this site, you are agreeing to our new Terms of Use.
You are viewing an older version of this Concept. Go to the latest version.

# Two-Step Equations and Properties of Equality

## Maintain balance of an equation while solving using addition, subtraction, multiplication, or division.

Estimated19 minsto complete
%
Progress
Practice Two-Step Equations and Properties of Equality
Progress
Estimated19 minsto complete
%
Taking Temperatures

Credit: Liz West
Source: http://www.flickr.com/photos/53133240@N00/3201760894/
License: CC BY-NC 3.0

If you’re watching the news and the meteorologist says that it’s going to be 30 degrees outside, how would you dress? Does the answer change if you’re visiting Italy? It should! 30 degrees in the U.S. is winter coat weather, but 30 degrees in Italy means shorts and a T-shirt. Why? Because the countries use two different scales of temperature.

#### Freezing, Boiling, and Everything In Between

The United States uses the Fahrenheit scale to measure temperature. On the Fahrenheit scale, water freezes at 32 degrees and boils at 212 degrees. 98.6 degrees is the human body temperature, and 30 degrees is a chilly winter day with a chance of snow. The Celsius scale sets the freezing point of water at 0 and the boiling point of water at 100. You can convert    between the scales by solving a two-step equation: \begin{align*}C = \frac{5(F-32)}{9}\end{align*}. For example, you can figure out what 30°C is in degrees Fahrenheit by solving the following equation:

\begin{align*}C & = \frac{5(F-32)}{9}\\ 270 & = 5(F-32)\\ 54 & = F-32\\ 86 & = F\end{align*}

So, 30°C is equivalent to 86°F, or a hot summer day.

Credit: Laura Guerin
Source: CK-12 Foundation
License: CC BY-NC 3.0

Most scientists use a third temperature scale: the Kelvin scale. 0 degrees Celsius is 273 degrees on the Kelvin scale. 0 on the Kelvin scale is absolute zero, the coldest temperature possible. The temperature in space is about 2.73 K. Scientists working in labs have tried to reach temperatures very close to absolute zero, and they’ve made some fascinating discoveries.

See for yourself: http://www.youtube.com/watch?v=TNUDBdv3jWI

#### Explore More

Watch the following videos to learn more about the different temperature scales and absolute zero.

### Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes
Please to create your own Highlights / Notes
Show More

### Image Attributions

1. [1]^ Credit: Liz West; Source: http://www.flickr.com/photos/53133240@N00/3201760894/; License: CC BY-NC 3.0
2. [2]^ Credit: Laura Guerin; Source: CK-12 Foundation; License: CC BY-NC 3.0

### Explore More

Sign in to explore more, including practice questions and solutions for Two-Step Equations and Properties of Equality.
Please wait...
Please wait...