Question

answer this question

Answer 1

Collect the like terms.
$\mathrm{Thus,} \\ 4(n)- (\frac{1}{n} + \frac{1}{n}+......+\frac{n}{n})\\ 4n- \frac{1}{n}\times (1+2+3+4+5+6+7.....+n)\\ 4n-\frac{1}{n} \times (\frac{n(n+1)}{2}) \\ =4n-\frac{(n+1)}{2}$

Answer 2

hey mate!

here is your answer,

a=4-1/n
d=4-2/n-4+1/n=-2/n+1/n=-2+1/n=-1/n
sn=n/2(2a+(n-1)d)
sn=n/2(2*4-1/n+(n-1)-1/n)


this is the equation after solving it you will get the value of sn.


hope it helped!