Looks like you just evaluated the summand for the given value of

, whereas the question is asking you to find the value of the sum for the first

terms.
Let

. Then

is the

th partial sum.

happens to be the first term in the series, which is why that box is marked correct:

But the next partial sum is not correct:

and this is not the same notion as the second term (which indeed is 0.75) in the series.
Answer:

Step-by-step explanation:
Coin toss:

Letter Selection:


If you use substitution the should be answer 30
<span> 2 square root of 7 − square root of 28
= 2</span>√7 - √28
= 2√7 - 2√7
= 0