Pairwise coding problem

I am having problem in this question.I dont know how to approachTell us what’s happening:

Your code so far

function pairwise(arr, arg) {
  return arg;
}

pairwise([1,4,2,3,0,5], 7);

Your browser information:

Your Browser User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36.

Link to the challenge:
https://www.freecodecamp.org/challenges/pairwise

Are you able to do the following?

var arr = [1,4,2,3,0,5];

// Using the given array, arr, generate the pairwise sums of the first number
// in the array with each of the rest of the numbers in the array, that is:
// 1 + 4 = 5;
// 1 + 2 = 3;
// 1 + 3 = 4;
// ... etc.

I am having problem in solving the question