1. payton says that rational expressions are not closed under addition, subtraction, multiplication, or division. his
claim is shown below. is he correct for each case? justify your answers.
a. x / 2x + 1 +x + 1 / 2x + 1 = 1, and 1 is a whole number, not a rational expression.

b. 3x − 1 / 2x + 1 − 3x − 1 / 2x + 1 = 0, and 0 is a whole number, not a rational expression.

c. x − 1 / x + 1 ∙x + 1 / 1 = x − 1, and x − 1 is a whole number, not a rational expression.

d. x − 1 / x + 1÷1 / x + 1 = x − 1, and x − 1 is a whole number, not a rational expression.