Answer
$M_y=-5$
$M_x=24$
So the center of mass is $\left(-0.28;1.33\right)$
Work Step by Step
$$M_y=m_1\cdot x_1+m_{2}\cdot x_2+m_{3}\cdot x_3+m_{4}\cdot x_4=5\cdot (-4)+4\cdot 0+3\cdot 3+6\cdot 1=-5$$
$$M_x=m_1\cdot y_1+m_{2}\cdot y_2+m_{3}\cdot y_3+m_{4}\cdot x_4=5\cdot 2+4\cdot 5+3\cdot 2+6\cdot (-2)=24$$
so the center of mass is:
$$\left(\frac{-5}{5+4+3+6}\approx -0.28;\frac{24}{5+4+3+6}\approx 1.33\right)$$
