symbolic substitution dfgsdfgs dfgsdfgs

So i have these equations

syms a b c x y z

eq1 = c == z+b;
eq2 = a == x+y;

s = subs(eq1,z,eq2)

what i am trying to do is very simple but just cannot figure it out.

i am trying to substitute z by a so i can have this expression c = x+y+b

but instead i have this monstrosity

s =
 
c == (a + b == b + x + y)
 

if i only do

s = subs(eq1,z,a)

it only substitute "a" but not the expression

s = 
c == a + b
 

how can i get it right ?

Answer 1

[madhan ravi]

subs(eq1,z,rhs(eq2))

[madhan ravi]

Alternatively if a is not isolated then:

subs(eq1,z,rhs(isolate(eq2,a)))