Linear equation with multiple values for a constant

Hi Everyone,

I am trying to solve these 2 equation simultaneously, Dx+4y=2, Dx+2y=4 for 2 values of D which are 1 and 3. I have written the code but it only gives 1 value. Help will be great. Thanks

>> D=[1 2];

for k=1:length(D)

Z=solve([D(k)*x+4*y==2,D(k)*x+2*y==4],[x,y])

end

Z =

    x: [1x1 sym]
    y: [1x1 sym]

Z =

    x: [1x1 sym]
    y: [1x1 sym]

>> Z.x

ans =

3

Answer 1

[Star Strider]

It will give both of them for both values of ‘D’ if you ask it to:

syms x y
D=[1 2];

for k=1:length(D)    
    Z{k} = solve([D(k)*x+4*y==2,D(k)*x+2*y==4],[x,y]);    
end

D1 = [Z{1}.x; Z{1}.y]
D2 = [Z{2}.x; Z{2}.y]

D1 =

    6
   -1

D2 =

    3
   -1

[Star Strider]

Ahsan Muhammad’s Answer moved here:

OMG you are a legend Star Strider, thank you so much Heres another query

S=solve([C1*(A*x+B1*y^(1/N1))^-1 + C2*(A*x+B2*y^(1/N2))^-1 == 1, x/(y*N1)*(C1*(A*x+B1*y^(1/N1))^-1) + x/(y*N2)*(C2*(A*x+B2*y^(1/N2))^-1)==1],[x,y])

This code runs fine, i have defined values for everything except x and y. But it takes 4 - 5 hours. Is there a faster way to do this?

[Star Strider]

Answered in http://www.mathworks.com/matlabcentral/answers/237116-taking-too-long-to-get-a-solution.