Evaluate the expression for x = 2 and y = 4 . (x ^ 5 * y ^ 7) / (x ^ 2 * y ^ 5) only numbers

How do i do this? i don’t understand

How does a low unemployment rate affect a nation's economy? a. the nation has a higher number of productive resources. b. the nation can spend more money on for unemployed people. c. the nation can save money by paying lower salaries to a large workforce. reset

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.