3x+6x+9x+....+to n terms= 3/2n(n+1)x
Answers
Answered by
18
3x + 6x + 9x + ......n terms
they are in AP
therefore, the common difference is 3x
sum = n/2 [2.3x + (n - 1) 3x]
=3*n (2 + n - 1)/2
=3/2 nx (1 + n)
Hence proved !
Answered by
5
Step-by-step explanation:
HOPE it will be helpful
Attachments:
Similar questions