Question

find the sum (4-1/n)+(4-2/n)+(4-3/n)+....upto n terms

Answer 1

Remove the brackets first,

You will get 4+4+4+4+....4(nterms ) = 4n,

4n - 1/n-2/n-3/n - .......- n/n

If you take LCM without taking 4,

Then it will be
$\frac{ \frac{n(n + 1)}{2} }{n} = \frac{n(n + 1)}{2n}$
Now the answer will be 4n - n(n+1)/2n ,

Hope you understand !!