I need help solving this as I believe the textbook solution in Crytography and Network Security, 7th Edition to be incorrect. Please explain how to solve in terms of Elucidian Algorithm and GCD

2.3 For each of the following equations, find an integer x that satisfies the equation a. 5x = 4(mod 3) b. 7x = 6(mod 5) c. 9x = 8(mod 7) 2.3 For each of the following equations, find an integer x that satisfies the equation a. 5x = 4(mod 3) b. 7x = 6(mod 5) c. 9x = 8(mod 7)