Question

1.1 the third term of an arithmetic sequence is 8 and the 15 term is 44 . Calculate: 1.1 the common difference and first term. 1.2 the sum of the first 50 terms. 1.2 1;4;7;10.... Is an arithmetic sequence .find: 1.2.1 the 30 term.

Answer 1

https://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html

Answer 2

http://www.mathsisfun.com/algebra/sequences-sums-arithmetic.html

might work better