Write a function called divisible that takes a matrix A of positive integers and a single positive integer k as its two inputs and returns a matrix B that has the same size as A. The elements of B are all divisible by k. If an element of A is divisible by k, then the corresponding element in B must have the same value. If an element of A is not divisible by k, then the corresponding element of B must be the product of the given element of A and k. You are not allowed to use any for-‐loops or while-‐loops. For example, the call
X = divisible([1 2 ; 3 4], 2)
would make X equal to [2 2 ; 6 4].