math
posted by DJ .
What is the difference between a expression and a equation?

Equation has an = sign and expression doesnt?

An expression is just an algebraic formula, like a + bx. It contains no equals (=) sign . An equation states that one algebraic expression equals another (or a number), and it has an = sign between the two expressions.
You could 2 + 2 = 4 is an equation, but it is a special kind called an identity, since it is always true.