(7x + 2)-(x^2 + 5) in Z_10 =
(a) 9x^2 + 7x + 7
(b) 9x^2+ 6x + 10
(c) 8x^2 + 7x + 6
(d) None of the mentioned
The question was asked in a national level competition.
The doubt is from Polynomial and Modular Arithmetic- III in portion Basic Concepts in Number Theory and Finite Fields of Cryptograph & Network Security