Just picked out a few examples from a practice exam.

1)Solving the equation az=1 mod m

(a) a=3 m = 10 (ANS = 7)

(b) a=5 m = 18

2)Solve the following congruence, equations for x.(Giving the solution in the form a mod m)

(a) 3x - 1 = 7 mod 10 (ANS = x = 6 mod 10)

Any chance of a step by step explanation on a few of them .