Just use a calculator.
First substitute in the numbers and make sure to use ( ) when plugging in negative values. For example, the first one says n=4, you can substitute n from the expression to 4. So n^2 + 3n + 8 will turn into 4^2 + 3(4) + 8 which is 16 + 12 + 8 = 36. You can do this with the other questions.
Number 10 is -213.