Solve the Problem $x + y = 9$ If $\delta ( x , y ) = x + y$

Multiple Choice

Solve the problem.
-Find the center of mass of a thin triangular plate bounded by the coordinate axes and the line $x + y = 9$ if $\delta ( x , y ) = x + y$

A) $\bar { x } = 3 , \bar { y } = 3$
B) $\bar { x } = 6 , \bar { y } = 6$
C) $\bar { x } = \frac { 27 } { 8 } , \bar { y } = \frac { 27 } { 8 }$
D) $\bar { x } = \frac { 15 } { 4 } , \bar { y } = \frac { 15 } { 4 }$