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.

Question

shamil98 · Answer

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

anonymous · Answer

9, 13, 17, 21?

anonymous · Answer

yay!! :)

shamil98 · Answer

yes.

anonymous · Answer

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

anonymous · Answer

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

shamil98 · Answer

yeah.

anonymous · Answer

so 9 & 45 :D

shamil98 · Answer

mhm.

anonymous · Answer

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

shamil98 · Answer

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

shamil98 · Answer

Understand what i did?

anonymous · Answer

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

shamil98 · Answer

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

anonymous · Answer

ahh i see now! thank you so much :)

shamil98 · Answer

no problem.