In this task you will be given a list of lists, of numbers. For every inner list, you should multiply every number in that list and put the results in your answer. The output should be a list of numbers with the same length as the number of the lists in the input list.
[[31, 4], [-12, -20, 49, 48], [49, 20, 50], [28, -48, 33, -3]]