Whole numbers are: 0, 1, 2, 3, 4, 5, 6, … Integers are: …, -4, -3, -2, -1, 0, 1, 2, 3, 4, … Any integer that is a negative number, like -3 or -546, can not be a whole number.
Let the attendees in opposition be x. This means that the attendees in favour are x+6. That means x+x+6=42, which is 2x+6=42, so 2x=36 and x=18. Therefore, there are 18 attendees who opposed it.
