ANSWER

EXPLANATION
The explicit rule for an arithmetic sequence is given by:

It was given that:

and

The common difference is

We plug in the values into the explicit formula to get,

Expand to get,

The explicit rule is

Solve for x by simplifying both sides of the equation, then isolating the variable.
Exact Form: x= 2/5
Decimal Form: x= 0.4
The answer is d because when you go from positive to negative you add the positive number to get to zero and than add the number you are getting to make sense?