Question

1 The value of 1+ - is 1 1+ 1 2+ 3​

Answer 1

Answer:

11+11+2+…+11+2+…+n

We know that1+2+…+n=n(n+1)2

Therefore, thenthterm is

Tn=1n(n+1)2=2n(n+1)=2(n+1−n)n(n+1)=2[1n−1n+1]

Thus -

T1=2[11−12]

T2=2[12−13]

T3=2[13−14]

⋮

Tn=2[1n−1n+1]

Adding we get-

T1+T2+T3…+Tn=2[1−1n+1]

Thus, Sum= 2nn+1

Answer 2

Answer:

26

Step-by-step explanation:

Let the blank line be x.

1+x is 11+12+3

x=26

THANKS,. ✏️✏️