It should be written as follows: {a | a = 2k 180+ 135, k ∈ z} ∩ {b | b = (2k+1)1.

2k 180+ 135 represents an even multiple of 180+ 135.

(2k+1) 180+ 135 represents an odd multiple of180+135.

Because odd and even numbers are integers.

So it is the sum of integer multiples of 180 and 135.

Just write it in a mathematical formula.

m 180 + 135 (m∈Z)

In fact, there is no need to use another letter m.

Let's write it like this: k * 180+ 135 (k ∈ z).

So:

{a|a=2k 180 + 135，k∈Z }∩{ B | B =(2k+ 1) 180+ 135，k∈Z } = { a | a = k * 180+ 135(k∈Z)}