6. Define a relation R on Z as (a, b) E R if and only if a and b, when written out, have the same number of 5s. For example, (1752, 95) E R since they both have one 5 but (1752, 505) ( R since 1752 has one 5 but 505 has two 5s. Is R an equivalence relation? Prove that R is an equivalence relation. This problem is similar to Example 4.6 and to Exercise 16 in Section 4.6 of your SNHU MAT299 textbook