Question

WILL GIVE BRAINLIES- ARITHMETIC SEQUENCE

Answer 1

Answer:

2,322,775

Step-by-step explanation:

$a_1=4\\\\a_i=a_{i-1}+11\\\\\implies a_2=a_{2-1}+11\\a_2= a_1+11 \\a_2= 4+11 \\a_2= 15\\\\d = a_2-a_1 \\d= 15-4 \\d= 11\\\\S_{650}=?\\\\\implies n = 650$

By the formula of sum of an Arithmetic Sequence

$S_n= \frac{n}{2} [2a_1+(n-1)d]\\\\S_{650}= \frac{650}{2} [2\times 4+(650-1)\times 11]\\\\S_{650}= 325 [8+649\times 11]\\\\S_{650}= 325 [8+7,139]\\\\S_{650}= 325\times 7,147\\\\\huge \red {\boxed {S_{650}=2,322,775}}$