First determine the common difference by the equation,
d = (an - a1) / (n - 1)
Using the given values,
d = (-226 - 26) / (22 -1) = -12
Then, determine the 31st term,
a31 = a1 + (31 - 1) x (d)
Substituting,
a31 = 26 + (30)(-12) = -334
Therefore, the 31st term is -334.
