Syntax error in Simulink

It shows that The expression: (1/(75.31*u(4)+167.36*u(5)+217.57*u(6)+334.37*u(7))*(0.84*(u(3)-u(2))+41840*exp(20.9057-(10000/(u(2)+275.15)))*x*(3)*u(5)+25105*exp(38.9057-(17000/(u(2)+273.15)))*u(4)*u(6))) has a syntax error. I don't know why it is wrong. Can someone help me? This is my first order equations

(1/(75.31*x(3)+167.36*x(4)+217.57*x(5)+334.37*x(6))*(0.84*(x(2)-x(1))+41840*exp(20.9057-(10000/(x(1)+275.15)))*x*(3)*x(4)+25105*exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)))
(1.6/200)*(u(1)-x(2))-(0.42*2)/(200*4.2)*(x(2)-x(1))-(0.084*4)/(200*4.2)*(x(2)-17)
-exp(20.9057-(10000/(x(1)+273.15)))*x(3)*x(4)-exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)
-exp(20.9057-(10000/(x(1)+273.15)))*x(3)*x(4)
exp(20.9057-(10000/(x(1)+273.15)))*x(3)*x(4)-exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)
exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)

Answer 1

[Fangjun Jiang]

Define a set of example value for u(1) to u(7) in MATLAB, copy and past your expression picece by piece in small parts and execute it in MATLAB, find which part causing the problem.

[Teo Adrian]

Actually I'm still newbie for this simulink. Can I pm u to ask?

[Teo Adrian]

This is my first order equation. If someone can help me to solve it, really thanks alot!

(1/(75.31*x(3)+167.36*x(4)+217.57*x(5)+334.37*x(6))*(0.84*(x(2)-x(1))+41840*exp(20.9057-(10000/(x(1)+275.15)))*x*(3)*x(4)+25105*exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)))
(1.6/200)*(u(1)-x(2))-(0.42*2)/(200*4.2)*(x(2)-x(1))-(0.084*4)/(200*4.2)*(x(2)-17)
-exp(20.9057-(10000/(x(1)+273.15)))*x(3)*x(4)-exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)
-exp(20.9057-(10000/(x(1)+273.15)))*x(3)*x(4)
exp(20.9057-(10000/(x(1)+273.15)))*x(3)*x(4)-exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)
exp(38.9057-(17000/(x(1)+273.15)))*x(3)*x(5)