Question

Find the value of n
(7 + 12i) =455​

Answer 1

Answer:

34

Step-by-step explanation:

7+12i=455

12i=455-7

= 448

i=448%12

=34

Answer 2

Answer:

9

Step-by-step explanation:

$S_{n} =n(a_{1}+a_{n})/2$

also:

$a_{n} =a_{1} +(n-1)d$

Input $a_{1} =67, d=7, S_{n}=455$

n=9