Use all four numbers 5, 1, 7, 9 with a value as close to 6000 as possible

What are potential hypotheses (explanations) regarding why there are ecological equivalents between many metatherians and eutherians? discuss your hypothesis in terms of the processes that could lead to the current ecologies and distributions of metatherians and eutherians.

When you answer this can you explain

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76