Question: how can i solve coupled equations in runge kutta method? :(

Hello guys

I have a problem in runge kutta method for coupled differential equations .For example consider these equations:

a*Φ''''(x)+b*Φ''(x)+c*Φ(x)+d*Ψ''(x)+e*Ψ(x):=0

d*Φ''(x)+e*Φ(x)+j*Ψ''(x)+h*Ψ(x):=0

The boundry conditions are:

Φ(0.83)=1;Φ'(0.83)=0;Φ(-0.83)=1;Φ'(-0.83)=0;Ψ(0.83)=1;Ψ(-0.83)=1

Φ(x) and Ψ(x) are unknown functions and a,b,c,d,e,j,h are constants . I want to get answers by runge kutta numerical method .

i used this form of algorithm but i cant do it :

 

please help me to solve these types of equations.

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