Set is a sum of two intervals :(1,4) u [2,6] In the first interval it is open on both sides so 1 and 4 don't belong to this interval, the second is closed so both 2 and 6 belong to interval and numbers between 2 and 6 We can write it as 1<x[tex] \leq 6[/tex] summing both sets we have one set: (1,6] so a) represent our set b) also represent because all numbers between 4-6 and 6 are in our set c)also represent, all numbers are in main set d)also represent
