Question

the sumbof 20 terms of an AP is 820. if the first term is 3 find the common differences​

Answer 1

Answer:

4

Step-by-step explanation:

Sn= n/2[2a+(n-1)d]

Sn=820,n=20,a=3

820=20/10[2×3+(20-1)d]

820=10[6+19d]

82=6+19d

76=19d

d=4

Answer 2

Answer:

here's your answer..

..d= 4.