The name of every student taking Algebra was listed alphabetically and numbered. The teacher uses an arithmetic sequence to call on students. The numbers of the first 3 students are listed below.
What will be the number of the 25th student chosen?
9,6, 3...

The number will be -63

Step-by-step explanation:

Here, we want to give the number of the chosen 25th student

We can see that the numbering follows an arithmetic sequence where a = 9 and d which is the common difference is (6-9) = -3

Mathematically, we can calculate the nth term using the equation below;

Tn = a + (n-1)d

in this case, n = 25, a = 9 and d = -3

So we have

Tn = 9 + (25-1)-3

Tn = 9 -3(24)

Tn = 9-72

Tn = -63

answer: 42

use a calculator to find that 845/73 = 11.575

the whole part of the answer is 11. multiply this by 73 to get 11*73 = 803.

subtract that result from 845 to get 845 - 803 = 42