Rearrange symbolic variables in equation

Suppose i have an equation a=b*(c-3) and i want to find a/b which is equal to (c-3). How do i code it. P.S I have tried the solve function

eqn = a == b*(c-3);

S = solve(eqn, a/b)

but the result is

S =

struct with fields:

b: [0×1 sym]

c: [0×1 sym]

Answer 1

[Walter Roberson]

syms aoverb
S = solve(subs(eqn, a, aoverb*b), aoverb)

Answer 2

[VBBV]

syms a b c ;
eqn = a/b == (c-3);
S = solve(eqn,[ a,b,c])

[jun wei]

Hi, i would like matlab to return S= (c-3) where S=a/b for the equation of a=b*(c-3).

[VBBV]

syms a b c ;
eqn = a/b == (c-3);
S = solve(eqn,[a,b])

S = struct with fields:
    a: c - 3
    b: 1

lhs(eqn) == S.a % do you mean like this ?

ans = 

[jun wei]

uhmm not exactly. For instant if a much complicated equation say a+y^2+3x=b*(2x+c) etc and i want to find a/b in terms of those symbolic variables.