Find the Midpoint of the Line Segment Joining the Points $$P _ { 1 } \text { and } P _ { 2 }$$

Multiple Choice

Find the midpoint of the line segment joining the points $$P _ { 1 } \text { and } P _ { 2 }$$
- $$\mathrm { P } _ { 1 } = ( 5 \mathrm { x } , 6 ) ; \mathrm { P } _ { 2 } = ( 6 \mathrm { x } , 7 )$$

A) $\left( \frac { 11 x } { 2 } , \frac { 13 } { 2 } \right)$
B) $( x , 1 )$
C) $( 11 \mathrm { x } , 13 )$
D) $\left( \frac { 13 x } { 2 } , \frac { 11 } { 2 } \right)$