Math
posted by Meghan on .
Okay, I need to find the 101th term of the sequence 5,9,13,17,21...
Do I do this:
a1 + (n1)d
SO...
5+(1011)4
5+(100)4
105x4
420
Did I do this problem correctly?

Almost!
First, check your formula against values:
a1+(n1)d
where a1=5, d=4, and n=term number
For the first term, n=1
5+(11)*4=5 correct
For the third term:
5+(31)*4=5+2*4=13 correct.
So there is a good chance the formula.
Now do the calculations for the 101th term:
5+(1011)*4
=5+100*4
Remembering that in all calculations, the priority of operations is in the order:
()
* or ÷
+ or 
So we need to multiply before add, or
5+100*4
=5 + (100*4)
=5 + 400
= 405