Question

How many terms of the Arithmetic Progressions 3,7,11,.........are needed for the sum to give the sum 300? Also find the last term of the AP?

Answer 1

sn= n/2(2a+(n-1)d)

300 = n/2 (6+ (n-1)4)

300 = n/2 (6+4n-4)

600= n( 2+4n)

600 = 2n + 4n 2

4n 2 +2n -600

plzzzz solve this after this
u can solve this by splitting the middle term...

Answer 2

this is your required answer.☺️