Describe the basic features of the relational data model and discuss their importance to the end user and the designer.

See the explanation below.

Step-by-step explanation:

The relational data model can be described as a techniques use in database management in which data are managed by employing a language and structure that is in line with first-order predicate logic.

A relational database is just one data repository which makes structural and data independence possible without losing conceptual simplicity.

The relational model is an achievement for users and designers as it gives them the opportunity to work in a conceptual setting that is simpler.

The the importance of the relational data model to the end users is that there data can now be visualized more easily as a group of data organized as a matrix.

Its importance to the designers is that do not have to have to experience again the difficulties related to physical data representation, and it is now easier for them to handle conceptual data representation.

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.