3 Four tools are attached to a board.
The board is to be modelled as a uniform lamina and the four tools as four particles.
The diagram shows the lamina, the four particles \(A , B , C\) and \(D\), and the \(x\) and \(y\) axes.
\includegraphics[max width=\textwidth, alt={}, center]{8ca9234e-1a01-4e35-8b1b-17c6039cf8d7-06_597_960_550_532} The lamina has mass 5 kg and its centre of mass is at the point \(( 7,6 )\).
Particle \(A\) has mass 4 kg and is at the point ( 11,2 ).
Particle \(B\) has mass 3 kg and is at the point \(( 3,6 )\).
Particle \(C\) has mass 7 kg and is at the point ( 5,9 ).
Particle \(D\) has mass 1 kg and is at the point ( 1,4 ).
Find the coordinates of the centre of mass of the system of board and tools.
[0pt] [5 marks]