I. Modular Arithmetic Exercise #1 How many equivalence classes in mod 117 Enumerate some of the elements We have 0->10 equivalence classes (11 equivalence classes): [O]:{ [1]: (2): (3): [5): [6] [7]: (8): [9]: [10]: Prove that if (a + b) = (a + c)mod p then b = c mod p and add a inverse in both side: OF(a+b) = a +ta+c) mod p b = c mod p If (a x b) = (a x c)mod p then b = c mod p. Multiply my a inverse cin both sides.: -1 Gaxha-10x)