??? Error using ==> maple
Error, rhs expects its 1st argument, e, to be of type {`..`, `::`, relation}, but received {x(t) = RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30)), y(t) = -20/3*(RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30))*(exp(-LambertW(exp(-51/40+3/100*RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30))+3/4*ln(30)+ln(-3/8)-3/4*ln(RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30)))))-51/40+3/100*RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30))+3/4*ln(30)+ln(-3/8)-3/4*ln(RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30))))+1)-RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30)))/RootOf(Int(1/_c/(exp(-LambertW(exp(-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)+ln(-3/8)-3/4*ln(_c))+1),_c = `` .. _Z)-t-Int(-8/_c/(3*exp(-LambertW(-3/8*exp(-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c)))-51/40+3/100*_c+3/4*ln(30)-3/4*ln(_c))-8),_c = `` .. 30))}

Error in ==> C:\MATLAB6p5\toolbox\symbolic\dsolve.m
On line 304  ==>    RRHS = maple('rhs',R); RLHS = maple('lhs',R);

Error in ==> C:\Documents and Settings\Administrator\桌面\Untitled4.m
On line 1  ==> [x,y]=dsolve('Dx=x*(1-0.15*y)','Dy=y*(-0.75+0.03*x)',... 

如果你用Matlab解提示错误如下：
[x,y]=dsolve('Dx=x*(1-0.15*y)','Dy=y*(-0.75+0.03*x)','x(0)=30','y(0)=2.5','t')
??? Error using ==> dsolve
Error, (in dsolve/IC) The 'implicit' option is not available when giving Initial Conditions.

去掉初值错误：
[x,y]=dsolve('Dx=x*(1-0.15*y)','Dy=y*(-0.75+0.03*x)','t')
Warning: Explicit solution could not be found; implicit solution returned.
> In dsolve at 312
??? Error using ==> dsolve
Too many output arguments.

 dsolve命令是符号求解微分方程，只有存在原函数的微分方程才能得出正确的解。否则，只能用数值解。￥￥￥原方程看似简单，应该有原函数.....哈哈哈

如果举例的话如下：能解
[x,y]=dsolve('Dx=3*y','Dy=0.03*x','x(0)=30','y(0)=2.5','t')
 
x =
 
55/2*exp(3/10*t)+5/2*exp(-3/10*t)
 
y =
 
11/4*exp(3/10*t)-1/4*exp(-3/10*t)