Definition: 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.
Input: [[42, 24, -4], [31, 37, 45], [-47, -21]]

[-4032, 51615, 987]