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, -7, 38, -16, -7], [9, -24, 34, 24, 21], [-22, 37, -31]]