Use sigma notation to write the sum.
$$\frac { 1 } { 3 \cdot 2 } + \frac { 1 } { 4 \cdot 3 } + \cdots + \frac { 1 } { 9 \cdot 8 }$$
A) $\sum _ { n = 1 } ^ { 7 } \frac { 1 } { ( n + 1 ) ( n + 2 ) }$
B) $\sum _ { n = 1 } ^ { 7 } \frac { 1 } { n ( n + 1 ) }$
C) $\sum _ { n = 1 } ^ { 7 } \frac { n } { ( n + 2 ) ! }$
D) $\sum _ { n = 1 } ^ { 5 } \frac { 1 } { ( n + 1 ) ( n + 2 ) }$
E) $\sum _ { n = 0 } ^ { 6 } \frac { 1 } { ( n + 1 ) ( n + 2 ) }$

Question

Quizplus · Accepted Answer

The correct answer is A because the sum can be written as $\sum _ { n = 1 } ^ { 7 } \frac { 1 } { ( n + 1 ) ( n + 2 ) }$.

Use Sigma Notation to Write the Sum 13⋅2+14⋅3+⋯+19⋅8\frac { 1 } { 3 \cdot 2 } + \frac { 1 } { 4 \cdot 3 } + \cdots + \frac { 1 } { 9 \cdot 8 }3⋅21​+4⋅31​+⋯+9⋅81​

Use Sigma Notation to Write the Sum $\frac { 1 } { 3 \cdot 2 } + \frac { 1 } { 4 \cdot 3 } + \cdots + \frac { 1 } { 9 \cdot 8 }$