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.
Answers
Answered by
1
a) Tn=13+(n-1)10
b)T100=13+(99*10)=203
c)S20=(20/2)*[2(13)+19(10)]=2160
b)T100=13+(99*10)=203
c)S20=(20/2)*[2(13)+19(10)]=2160
Answered by
1
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.
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