Question

What is the 30th term of the arithmetic series 4, 7, 10, ...?

Answer 1

the answer is 91

Explanation:

Answer 2

for from 4 to 7, 3
from 7 to 10, 3

so, 3 is the "common difference" then


`\bf n^(th)\textit{ term of an arithmetic sequence}\\\\ a_n=a_1+(n-1)d\qquad \begin{cases} n=n^(th)\ term\\ a_1=\textit{first term's value}\\ d=\textit{common difference}\\ ----------\\ a_1=4\\ d=3\\ n=30 \end{cases} \\\\\\ a_(30)=4+(30-1)3\impliedby 30^(th)\textit{ term's value}`