binomial means there are two terms, so c² − 16 is the answer
mononomial means there is only one term, so -8c is the answer
written in descending form means from the highest degree (exponent) to the lowest, 4x² − 3x + 9 is the answer for question 3.
Question 4: use the same method for question 3, the third term is -7x
Question 5: not sure what this is: 2x2y. Is it 2x²y or 2x2y?
you need to add up the exponent of x and y. In this case, the highest degree is y's 4th power plus x's 1st power, which makes a 5.