By Kimberly Amadeo. Definition: Silicon Valley is the center for innovative technology companies. It's located in the are around San Francisco, California.It's home to 2,000 tech companies, the densest concentration in the world. This proximity to suppliers, customers, and cutting edge research gives each a competitive advantage.ilicon Valley Companies. The most well-known Silicon Valley companies include Adobe, Apple, Cisco, eBay, Facebook, Google, Hewlett-Packard, Intel, Intuit, Netflix, Oracle, Salesforce.com, Tesla, Twitter, Yahoo! and Zynga.
Math definition of Substitution: Substitution - A strategy for solving systems of equations that include solving for one variable and using that solution to find the other variable. 1  Subject : Math.  Topic : Algebra 2.
Subtraction in mathematics means you are taking something away from a group or number of things. When you subtract, what is left in the group becomes less. An example of a subtraction problem is the following: 5 - 3 = 2. Notice that there are three parts to the subtraction problem shown. The part you start with is called the minuend.