方程组有36个，未知数为x1-x34,xa,xb，除了未知数，其他都已知，其中两个方程组是定积分，两个上限为未知量，分别为,xa,xb，下限皆为0.初值为

x0=[0.036 0.055 0.04 0.032 0.028 0.031 0.06 0.05 0.05 0.03 360 0.04 0.06 0.05 0.034 0.028 0.03 0.062 0.05 0.055 0.04 365 0.91 0.87 0.89 0.86 0.9 0.88 0.85 0.89 0.88 0.9 5900 20]；

xa0=0.01;

xb0=0.01;

开始做了不合理的简化，只解了前f(35),f(36),f(1)-f(11)，解释合理的，现在不做简化，四个组分一起列式子，方成数变多，方程组总是不能得到合理的解，请高手指点，如何解这个方程组，小女子不胜感激，由于积分显示不出来，我上传了附件和图片。谢谢各位大神

fff(35)=( K/k1)*∫_0^xa▒〖CA0/(K*CA0*CB0-CC0*CD0-(K*(CA0^2+CA0*CB0)+(CA0*CC0+CA0*CD0)).*x+(K-1)*CA0^2.*x.^2)dx〗 -Lc1/U

fff(36)= =( K/k1)*∫_0^xb▒〖x(11)/(K*x(11)*x(22)-x(33)*x(34)-(K*(x(11)^2+x(11)*x(22))+(x(11)*x(33)+x(11)*x(34))).*x+(K-1)*x(11)^2.*x.^2)dx〗 –Lc2/U

fff(1)=xa-(xa1-x(8))/xa1;

fff(2)=h1/HETP1-(x(4)-x(6))/(K1*x(7)-x(6));

fff(3)=L*(S1+S3+S5)/V*S-(x(4)-x(6))/(xa1-x(7));

fff(4)=x(2)-(x(7)*(S1+S3+S5)+x(8)*(S2+S4))/S;

fff(5)=h2/HETP2-mi*(x(6)-x(5))/(K1*x(11)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4)-mi*x(5));

fff(6)=L/V-mi*(x(6)-x(5))/(mi*x(2)-x(11)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4));

fff(7)=h3/HETP3-(HETP4*x(5)-h4*(K1*x(1)-ya1)-ya1*HETP4)/(K1*HETP4*x(9)-h4*(K1*x(1)-ya1)-ya1*HETP4);

fff(8)=L*(S2+S4)/V*S-(HETP4*x(5)-h4*(K1*x(1)-ya1)-ya1*HETP4)*mi/(HETP4*(xa1*M1+xb1*M2+xc1*M3+xd1*M4-mi*x(9)));

fff(9)=xb-(x(11)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4)-mi*x(10))/(x(11)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4));

fff(10)=x(3)-(x(10)*(S1+S3+S5)+x(9)*(S2+S4))/S;

fff(11)=L/V-(h4/HETP4)*(K1*x(1)-ya1)/(x(3)-x(1));

fff(12)=xa-(xb1-x(19))/xa1;

fff(13)=h1/HETP1-(x(15)-x(17))/(K2*x(18)-x(17));

fff(14)=L*(S1+S3+S5)/V*S-(x(15)-x(17))/(xb1-x(18));

fff(15)=x(13)-(x(18)*(S1+S3+S5)+x(19)*(S2+S4))/S;

fff(16)=h2/HETP2-mi*(x(17)-x(16))/(K2*x(22)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4)-mi*x(16));

fff(17)=L/V-mi*(x(17)-x(16))/(mi*x(13)-x(22)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4));

fff(18)=h3/HETP3-(HETP4*x(16)-h4*(K2*x(12)-yb1)-yb1*HETP4)/(K2*HETP4*x(20)-h4*(K2*x(12)-yb1)-yb1*HETP4);

fff(19)=L*(S2+S4)/V*S-(HETP4*x(16)-h4*(K2*x(12)-yb1)-yb1*HETP4)*mi/(HETP4*(xa1*M1+xb1*M2+xc1*M3+xd1*M4-mi*x(20)));

fff(20)=xb-(x(22)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4)-mi*x(21))/(x(11)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4));

fff(21)=x(14)-(x(21)*(S1+S3+S5)+x(20)*(S2+S4))/S;

fff(22)=L/V-(h4/HETP4)*(K2*x(12)-yb1)/(x(14)-x(12));

fff(23)=xa-(x(30)-xc1)/xa1;

fff(24)=h1/HETP1-(x(26)-x(28))/(K3*x(29)-x(28));

fff(25)=L*(S1+S3+S5)/V*S-(x(26)-x(28))/(xc1-x(29));

fff(26)=x(24)-(x(29)*(S1+S3+S5)+x(30)*(S2+S4))/S;

fff(27)=h2/HETP2-mi*(x(28)-x(27))/(K3*x(33)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4)-mi*x(27));

fff(28)=L/V-mi*(x(28)-x(27))/(mi*x(24)-x(33)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4));

fff(29)=h3/HETP3-(HETP4*x(27)-h4*(K3*x(23)-yc1)-yc1*HETP4)/(K3*HETP4*x(31)-h4*(K3*x(23)-yc1)-yc1*HETP4);

fff(30)=L*(S2+S4)/V*S-(HETP4*x(27)-h4*(K3*x(23)-yc1)-yc1*HETP4)*mi/(HETP4*(xa1*M1+xb1*M2+xc1*M3+xd1*M4-mi*x(31)));

fff(31)=xb-(mi*x(32)-x(33)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4))/(x(11)*(xa1*M1+xb1*M2+xc1*M3+xd1*M4));

fff(32)=x(25)-(x(32)*(S1+S3+S5)+x(31)*(S2+S4))/S;

fff(33)=L/V-(h4/HETP4)*(K3*x(23)-yc1)/(x(25)-x(23));

fff(34)=(mi-(x(11)-x(22)-x(33))*(xa1*M1+xb1*M2+xc1*M3+xd1*M4))/(xa1*M1+xb1*M2+xc1*M3+xd1*M4)-x(34);