Question

28. Find the sum of the first 22 terms of an AP whose common
difference is 7 and the 22nd term is 149.​

Answer 1

Answer:

tell the first term of the AP please

Answer 2

Sn = 1661

Step-by-step explanation:

n=22

d=7

$a+21d=149\\a+21\times7=149\\a+147=149\\a=2\\\\sn=\frac{n}{2}(2a+(n-1)d\\sn=\frac{22}{2}(2\times2+(22-1)7\\sn=11(4+(21)\times7\\sn=11(4+147)\\sn=11\times151\\sn=1661$