1. Let a and b be real numbers. Define an operation * by a*b=a. a. Is the set of real numbers closed under the operation *? Why or why not? b. Is the operation * commutative on the set of real numbers? Why or why not? c.  Is the operation * associative on the set of real numbers? Why or why not?

Proficiency Redos Proficiency #5. [Set builder notation] a. Write the set A = {1,3, 4, 5, 7} in set builder notation without using any of the numbers in A. b. Write “the set of integers that are the product of the squares of two integers" in set builder notation, without using any words. (As an example, 36 = 2²32 is in this set.)

If x represents a positive real number, which expression is equivalent to vx23-Vx5 (use the one below)? * (30 Points) 10 10 O 19

W 3. Simplify the expression using order of operations: 25 - 5+ - 6(7) -18 1.56 -1.56 18 99+ O Type here to search 近