Unrecognized function or variable h.

trying to get equation to solve for the unknow variable H.

me = 2500;

m = 5 ;

gravity = 9.8;

me(2500) = h*m*g

Answer 1

[Torsten]

syms me m gravity h
eqn = me == h*m*g;
Sval = solve(eqn,h);
me_num = 2500;
m_num = 5 ;
gravity_num = 9.8;
Sval_num = subs(Sval,[me m gravity],[me_num m_num gravity_num])

Answer 2

[Voss]

This line:

me(2500) = h*m*g

says to set the 2500th element of the variable me equal to h*m*g.

m is defined, but h and g are not. This is the cause of the error.