Definition of dray. : a vehicle used to haul goods; especially : a strong cart or wagon without sides.
Expressions versus Equations. A difference between expressions and equations is what each represents. An expression shows a math relationship. One key to an expression is that there is no solution. An expression does not have an answer. An expression, however, can be evaluated. To evaluate an expression, substitute values for the variables.
Now it is time to talk about equations. An expression is just a statement like. 2 x + 3. This expression might be equal to any number, depending on the choice of x. For example, if x = 3 then the value of this expression is 9. But if we are writing an equation, then we are making a statement about its value.