分析如下：令  
编程如下：
clear all
[x,y,z,m]=dsolve('1.6*Dx-1.6*Dy+1000*x+210000=0','1.6*Dx+3.2*Dy-1.6*Dz+1000*y=0','1.6*Dy+3.2*Dz-1.6*Dm+1000*z=0','-1.6*Dz+3.2*Dm+1000*m=0','x(0)=-729.3','y(0)=-726.8','z(0)=-726.8','m(0)=-726.9')
 [x,y]=dsolve('2*Dx+Dy-y=exp(-t)','Dx+x+y=0','x(0)=1.5','y(0)=0')

结果很长，用ode函数比较好吧。