Question

Find the sum of first 24 term of the list of number whose nth term is given an=3+2n

Answer 1

ANSWER

an=3+2n

when n=1

3+2[1]=5

first term =5

when n=2

3+2[2]=7

second term =7

a=5,d=2,

Answer 2

ᴛʜᴇ ɴᴛʜ ᴛᴇʀᴍ ɪs ᴀɴ=3+2ɴ sᴏ ʙʏ ᴜsɪɴɢ ᴛʜɪs ᴡᴇ ᴄᴀɴ ғɪɴᴅ ᴛʜᴇ ᴠᴀʟᴜᴇ ᴏғ ᴛᴇʀᴍs ʟɪᴋᴇ ᴀ1=5,ᴀ2=7,ᴀ3=9

ᴀɴᴅ ᴀ24=51 

ɴᴏᴡ ᴛʜᴇ ғɪʀsᴛ ᴛᴇʀᴍ ɪs 5 ᴀɴᴅ ᴛʜᴇ ʟᴀsᴛ ᴛᴇʀᴍ ɪs 51 ᴀɴᴅ ᴛʜᴇ ᴅɪғғᴇʀᴇɴᴄᴇ ɪs 2

ʙʏ ᴜsɪɴɢ ᴛʜᴇ ғᴏʀᴍᴜʟᴀ ғᴏʀ sᴜᴍ ᴏғ ɴ ᴛᴇʀᴍs ɪ. ᴇ 

sɴ =ɴ/2(2ᴀ+(ɴ-1)ᴅ)

sᴏ s24=24/2(10+23*2) ɪ. ᴇ 672 ᴀɴs.

ʜᴏᴘᴇ ᴛʜɪs ʜᴇʟᴘs :)