i dont understand why the answers is 2

Question

var a = 4 + 2
var b = 15 - a
var result = a/(b-a)

Anyone please step by step to tell me how can the result is 2? Please

Answer 1

After solving
var a = 6
var b = 9
Taking brackets first
b-a = 3
a/(b-a) = 6/3 = 2
so result is 2

Answer 2

var a = 4 + 2
a is 6
var b = 15 - a
b is 9
var result = a/(b-a)
(b-a) = (9 - 6) = 3
a/3 = 6/3 = 2