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: [[-31, 8], [19, 11, 45, 18], [2, -2], [18, -7, 13, 3]]

[-248, 169290, -4, -4914]