For questions 4 – 9, find the sum or difference of the polynomials. Write your answer in descending order.
4. (9x2 + 3x - 2) + (3x2 – 5x -
5. (3x2 – 3x + 6) – (5x2 + 2x + 9)
6. (-3x2 + 2x + 1) + (-8x2 + 3x + 2)
7. (2x2 + 5x – 12) – (-4x2 + 2x+6)

Examine the following sets of events. set a: {1, 5, 7, 9, 14} set b: {2, 5, 6, 8, 14, 17} which of the following represents the intersection of set a and set b ? {∅} {5, 14} {1, 2, 5, 6, 7, 8, 9, 14, 17} {1, 2, 6, 7, 8, 9, 17}

The amount of money, in dollars, in an account after t years is given by a = 1000(1.03)^t. the initial deposit into the account was $_^a0 and the interest rate was _a1% per year. only enter numbers in the boxes. do not include any commas or decimal points^t. the initial deposit into the account was $__^a0 and the interest rate is % per year.

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.