ring over Q in countably many variables. Let I be the ideal of R generated by all polynomials -Pi where p; is the ith prime. Let RnQ1,2, 3, n] be the polyno- mial ring over Q in n variables. Let In be the ideal of Rn generated by all ] be the polynomial rin 9. Let R = QlX1,22.Zg, 2 polynomials -pi, where pi is the ith prime, for i1,.,n. . Show that each Rn/In is a field, and that...
(4) Let p Z be a prime. Prove that zli/(p+1) has exactly ] p2 +1 elements. Use that 5+5i (2+i)(3+i) to determine how many elements Zu/5+5i) has. (5) Let m,n be integers with m|n. Prove that the surjective ring homomor- phism Z/n -> Z/m induces a group homomorphism on units, and that this group homomorphism is also surjective. (4) Let p Z be a prime. Prove that zli/(p+1) has exactly ] p2 +1 elements. Use that 5+5i (2+i)(3+i) to determine...