Question

Consider the arithmetic sequence 13,23,33....
a. What is the algebraic expression for this sequence?
b. Find the 100th term of the sequence?
c. Find the sum of first 20 terms of this sequence.
pls answer the question correctly....I will Mark you as brainlist.​

Answer 1

a) Tn=13+(n-1)10

b)T100=13+(99*10)=203

c)S20=(20/2)*[2(13)+19(10)]=2160

Answer 2

Answer:

b. Here,

a= 13 , d = 10 ( difference between the second and first term)

so, by formula

100th term = a + 99d

= 13 + 99 × 10

= 13 + 990

= 1003

c. First, we need to find the 20th term

20th term = a + 19d

= 13 + 19 × 10

= 13 + 190

= 203

The sum first 20 terms = a + 20th term

= 13 + 203

= 216

sorry, I can't solve a.