If you ever plug a value in for a variable into an expression or equation, you're using the Substitution Property of Equality. This property allows you to substitute quantities for each other into an expression as long as those quantities are equal. Watch this tutorial to learn about this useful property!
An expression is just a mathematical phrase. In this tutorial, you'll learn about two popular types of expressions: numerical and algebraic expressions. A numerical expression contains numbers and operations. An algebraic expression is almost exactly the same except it also contains variables. Check out this tutorial to learn about these two popular kinds of expressions!
You can't do algebra without working with variables, but variables can be confusing. If you've ever wondered what variables are, then this tutorial is for you!
If you're trying to simplify some math expressions, you have to do it in the right order. If you've ever wondered how to do that, check out this example tutorial where you'll see exactly what order you need to follow:)
Plugging variables into an expression is essential for solving many algebra problems. See how to plug in variable values by watching this tutorial.