Can you help with 1,2,3,4. Thank you very much

Exercise 16 Bounds 1. Show that if I is a positive real number then a + 1 is not a lower bound for N. 2. Show that if b is an upper bound for a non-void set S C R then every c'> b is also an upper bound for S. 3. Give an example of a non-void bounded set S C R which contains an upper bound but does not contain a lower bound. 4. Show that a non-void set S C R cannot contain two different upper bounds. 5. Show that the set of real numbers of the form x/ y with (x| > ly| >0 is not bounded above or below. 6. Show that the set of real numbers of the form x/y with ly| > (x| > 0 is bounded. Find explicit upper and lower bounds and prove your answers are correct. 7. Suppose SC T C R are non-void sets. If S