# The Knewton Blog

Our monthly newsletter features edtech and product updates, with a healthy dose of fun Knerd news.

## Video: The Basics of Independent and Dependent Equations

Posted in Test Prep on March 20, 2011 by

//

In this video, Jess and Rich cover the basics of independent and dependent equations on Data Sufficiency questions. Here are some of the concepts they discuss:

• Systems of equations are dependent if one equation can be formed by manipulating and/or combining the others.
• If no manipulation/combination can create dependent equations, the equations are said to be independent.
• We need n independent equations to solve for a system with n variables.
• Dependent equations give us redundant information, so they don’t help us solve for all variables.
• If we try to solve a system with dependent equations, we will find that doing so is impossible. We will end up with an identity.

Check out the video for more detailed explanation and examples! For more Data Sufficiency help, be sure to check out past installments of this quantitative strategy lesson.