If the 100th term of an arithmetic sequence is 287, and its common difference is 3, then:

Question

If the 100th term of an arithmetic sequence is 287, and its common difference is 3, then

its first term a1 = ________

its second term a2 = ________

its third term a3 = _______

Hint: Use an =a1 + (n-1) d

Answer 1

a100 = 287 = a1 + 3(287-1)

a1 = 287 -3(286)

a1 = 287- 858

a1 = - 571

a2 = -568

a3 = - 565.

Answer 2

287 = a₁ + 286(3)

Can you solve for a₁ and answer?

(Should also become familiar with the formulas)