Question

What is the 100th term of the sequence 7, 4, 1, -2 ...

Answer 1

The sequence is arithmetic as it goes down 3 every time

Arithmetic nth term formula is an=a1+d(n-1)

an=7-3(n-1)
an=7-3n+3
an=-3n+10

To find the 100th term substitute n for 100
a100=-3(100)+10
a100=-300+10
a100=-290

The 100th term is -290