In an amphitheater, there are 20 seats in the front row, 23 seats in the second row, 26 seats in the third row, and so on, in an arithmetic sequenc A) Write an explicit formula to find an. the number of seats in the nº row. B) The last row in the amphitheater has 83 seats in it. How many rows a seats are there?

C) Write an expression using sigma notation that represents the total number of seats in the amphitheater.

D) Evaluate this expression. How many total seats are there?

Abouncy ball is dropped such that the height of its first bounce is 5.5 feet and each successive bounce is 64% of the previous bounce's height. what would be the height of the 7th bounce of the ball? round to the nearest tenth (if necessary).

Find the quotient. 50a2 – 98b2 -5a +7b

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.