Write a rule for the sequence.

Question

5, –4, –13, –22,…
• Start with –9 and add 5 repeatedly.
• Start with 5 and add 9 repeatedly.
• Start with 5 and subtract –9 repeatedly.
• Start with 5 and add –9 repeatedly.

Answer 1

The correct answer is: Start with 5 and subtract 9 repeatedly.

The sequence is decreasing by 9 each time, so the rule is to subtract 9 from the previous term to get the next term. Therefore, the rule for the sequence is:

an = a1 + (n-1)d

where a1 = 5, d = -9, and n is the term number.

Answer 2

AAAaannndd the bot gets it wrong yet again!

while the bot is correct, that was not one of the choices. The correct answer was

Start with 5 and add –9 repeatedly.