Use Summation Notation
-$$\sum _ { i = 3 } ^ { 6 } \frac { 1 } { i + 9 }$$
A) $\frac { 543 } { 1820 }$
B) $- \frac { 51 } { 20 }$
C) $\frac { 40 } { 9 }$
D) 54

Question

Quizplus · Accepted Answer

The given summation notation can be expanded and calculated as follows: $$\sum _ { i = 3 } ^ { 6 } \frac { 1 } { i + 9 } = \frac { 1 } { 3 + 9 } + \frac { 1 } { 4 + 9 } + \frac { 1 } { 5 + 9 } + \frac { 1 } { 6 + 9 }$$ Simplifying each term gives: $$\frac { 1 } { 12 } + \frac { 1 } { 13 } + \frac { 1 } { 14 } + \frac { 1 } { 15 }$$ Finding a common denominator and adding these fractions results in $\frac { 543 } { 1820 }$, which matches option A.

Use Summation Notation - ∑i=361i+9\sum _ { i = 3 } ^ { 6 } \frac { 1 } { i + 9 }i=3∑6​i+91​

Use Summation Notation
- $\sum _ { i = 3 } ^ { 6 } \frac { 1 } { i + 9 }$