How to solve (ax+2by) = -5 & (-3x+2by) = 7, in MAT Lab by symbolic math add ons?

Solve (ax+2by) = -5 & (-3x+2by) = 7, in MATLab by symbolic math add ons?

[Dyuman Joshi]

What are a and b supposed to be?

Also look into syms

[Jawed]

I want this solution for variable 'x' and 'y', 'a' & 'b' are constant. Thanks.

Answer 1

[Anish Gupta]

Hello,

As per my understanding, you want to symbolically solve two equations. However, it is not clear from your question, for which variable you want to solve the questions. So, I am assuming you want to solve for either 'x' and 'y', or 'a' and 'b'. Here is a code which shows how to do this:

syms x y a b
eqn=[a*x + 2*b*y==(-5),-3*x+2*b*y==7];
solve(eqn,[x,y])

ans = struct with fields:
    x: -12/(a + 3)
    y: (7*a - 15)/(2*(3*b + a*b))

Here is the solution for variables 'a' and 'b'

solve(eqn,[a,b])

ans = struct with fields:
    a: -(3*(x + 4))/x
    b: (3*x + 7)/(2*y)

I hope this resolves your query

[Jawed]

Thank you very much for providing solution. I want this solution for variable 'x' and 'y'. Thanks again.

[Anish Gupta]

The solution for 'x' and 'y' are the first three lines of the code

syms x y a b
eqn=[a*x + 2*b*y==(-5),-3*x+2*b*y==7];
solve(eqn,[x,y])

ans = struct with fields:
    x: -12/(a + 3)
    y: (7*a - 15)/(2*(3*b + a*b))