Question

Find the 50th term of the sequence 5, –2, –9, –16, ...

Answer 1

The sequence 5, -2, -9, -16... is a arithmetric sequence with the difference between a number and its succeding term is -7. The formua for getting the nth term of an arithmetric sequence is 
$a_n = a_1 + (n-1)d$
where $a_n$ is the nth term
$a_1$ is the first term
n is the number of terms
d is the difference

The first term in the sequence is 5. You need to find the 50th term so n is 50. The difference (d) is -7. Substituting these values in the equation, we get the final answer
$a_{50} = 5 + (50-1)(-7) \\ a_{50} = -338$

The 50th term is -338.

Answer 2

The correct answer: -338