Expression vs. Equation
Date: 03/20/2003 at 20:02:33 From: Mary Hahn Subject: It is about expressions and equations What is the difference between an expression and an equation?
Date: 03/20/2003 at 22:40:18 From: Doctor Peterson Subject: Re: It is about expressions and equations Hi, Mary. An equation is a mathematical "sentence" that says that two things are equal; for example 3x + 1 = 5 says that if you multiply x by 3 and add 1, you will get 5. An expression is a mathematical "phrase" that stands for a single number; for example, 3x + 1 is an expression whose value is three times the value of x, plus 1, whatever value the variable x might have. An expression can also be a single number or variable, since those have a numerical value. An equation consists of two expressions connected by an equals sign. It can only be true or false. An expression is never true or false, but just has a numerical value. We might add, by the way, that a variable is a mathematical pronoun, which can stand for some value. If you have any further questions, feel free to write back. - Doctor Peterson, The Math Forum http://mathforum.org/dr.math/
Search the Dr. Math Library:
Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.