Question

find the sum of 0.7+0.77+0.777+.... n=​

Answer 1

Answer:

Step-by-step explanation:

Sorry pa I don't know the answer. Make your answer clear

Answer 2

Answer:

7/81[9n-1+10^{-n}]

Step-by-step explanation:

Since we have given that

0.7+0.77+0.777+.......................

We can rewrite it as :

7/10+7/100+777/1000+..............

Insert 9 and take out 7:

7/9(0.9+0.99+0.999+..............)7/9(9/10+99/100+999/1000+.................)

So, it becomes

7/9[(1-0.1)+(1-0.01)+(1-0.001)+................]7/9(1+1+1+...................)-0.1+0.01+0.001+.7/{9}(n-{0.1(1-0.1^n}/{1-0.1})7/81[9n-1+10^{-n}]

Hence, the sum would be 7/81[9n-1+10^{-n}]