Question

Find the sum of these series.
a 4 + 7 + 10 + 13 + ... (20 terms) b 3 + 5 + 7 + 9 + ... (30 terms)
c 150 + 145 + 140 + 135 + ... (10 terms) d -15 + (-12.5) + (-10) + (50 terms)
e (x + 1) + (2x + 1) + (3x + 1) + ... + (21x + 11)​

Answer 1

Answer:

(a) sum of 20 terms are 650

(b) sum of 30 terms are 960

(c) sum of 10 terms are 1275

(d) sum of 50 terms are 2312.5

(e) (21x+10)(11x+6)/x