Jesse D. answered • 01/29/20

Patient and Experienced Mathematics and Spanish Tutor

Hi there! I would love to help you out.

The explicit formula for an arithmetic sequence is:

a_{n} = a_{1} + d(n-1) where a_{1} is your first term, d is your difference, and n is the number of terms.

We can plug in the given information into the formula now:

a_{n} = -34 + -2(n - 1)

To find the first three terms we can do one of two things. Either plug in 2, 3, and 4 (we don't plug in 1 because a_{1} is already given) in for n and record the results or we can just add our difference to the first term given:

a_{2} = -34 + -2(2-1) = -36

a_{3} = - 34 + -2(3-1) = -38

a_{4} = -34 + -2(4-1) = -40

There you have it! I hope this explanation was thorough and answered all of your questions. If you have any additional questions please don't hesitate to reach out! Learn on! :)

Eva M.

yea thanks, I had aha moments, this really helped me to solve the other problem!01/29/20