First you have all ten books, but then every time after, you loose one because you can't put the same book in the group twice.
10 * 9 * 8 * 7 = 5040 groups
Answer:
the answer is -32t + 67
Step-by-step explanation:
-16t2 +64 + 3
= -16t x 2 +64 +3
= -32t +67
We are given the first term and the common ratio, this means they belong to a geometric series.
For the given series:

Each term of the geometric series is obtained by multiplying the previous term by common ratio.
So the next terms will be:
-4.5, -6.75, -10.125, -15.1875, -22.78125
The general formula for the G.P would be:

On plotting the series, the result will be like this: