Question

For the sequence given by an (a sub n) = 4n+5, find the first 4 terms of the sequence by substituting n=1,2,3,4 into the equation.

Answer 1

me to the rescue lmao.
a(1) = 4 + 5 = 9
a(2) = 8 + 5 = 13
a(3) = 12 + 5 = 17
a(4) = 16 + 5 = 21

Answer 2

9, 13, 17, 21?

Answer 3

yay!! :)

Answer 4

yes.

Answer 5

now how would i identify the 1st term and the 10th term of the sequence?

Answer 6

would the first term be 9 and the last term is 4(10)+5?

Answer 7

yeah.

Answer 8

so 9 & 45 :D

Answer 9

mhm.

Answer 10

how would i use the first and tenth term to find the sum of the first tenth terms?

Answer 11

S(10) = 1/2(45+9)(10)
S(10) = 22(10)
S(10)= 220

Answer 12

Understand what i did?

Answer 13

well with the 45+9, what happened to the 54?

Answer 14

the sum of the 10th term = 1/2(if a(1) + if a(10)) x 10
45+9 = 54
1/2(54) = 22

Answer 15

ahh i see now! thank you so much :)

Answer 16

no problem.