Question

The 15th term of an arithmetic series is 143 and 13th term is 183.
a. Find the first term and common difference.
b. Find the 100th term of the series

Answer 1

Answer:

-1557

Step-by-step explanation:

a+14d= 143

a+12d= 183

-----------------

2d= -40

d= -20

a = 183 + 240= 423

a(100th)= 423+99*-20= 423-1980= -1557

Answer 2

d= - 20

a = 423

100th term is -1557