Combining symbolic differential equations

Hello,

I have the following two equations:

syms R C positive
syms u_e(t) u_a(t) i(t)
eq1 = u_e(t) == R * i(t) + u_a(t)

eq1 = 

eq2 = i(t) == C * diff(u_a(t), t)

eq2 = 

I want to use the expression i(t) of equation 2 in equation 1. Using solve does not help.

solve(eq2, i(t))

Warning: Solutions are parameterized by the symbols: [z1, z2], z2. To include parameters and conditions in the solution, specify the 'ReturnConditions' value as 'true'.

Warning: Solutions are only valid under certain conditions. To include parameters and conditions in the solution, specify the 'ReturnConditions' value as 'true'.

ans = struct with fields:
    C: z1
    t: z2

Could anyone give me a hint, how to do this?

Michael

[Michael]

Meanwhile I found the following solution:

syms R C positive
syms u_e(t) u_a(t) i(t)
syms U_0 real
Gl1 = u_e(t) == R * i(t) + u_a(t)

Gl1 = 

Gl2 = i(t) == C * diff(u_a(t), t)

Gl2 = 

Gl3 = subs(Gl1,lhs(Gl2), rhs(Gl2))

Gl3 = 

Thank you for your discussion.