function solve(){

    let solution = {
        add: (arr1,arr2) => [arr1[0]+arr2[0], arr1[1]+arr2[1]],
        multiply: (arr1,num) => [arr1[0]*num, arr1[1]*num],
        length: (arr) => Math.sqrt((arr[0]**2 + arr[1]**2)),
        dot: (arr1,arr2) => (arr1[0]*arr2[0] + arr1[1]*arr2[1]),
        cross: (arr1,arr2) => (arr1[0]*arr2[1] - arr2[0]*arr1[1])
    };

    return solution;
 }