How to solve equations using letters and variables

Hello World,

I have built a code for calculation of deflection from direct stiffness method. Now I have elements in the formula like (length, Elastic modulus, MOI, Torsional constant, Area). I have 32 members in my frame. I want to assign a variable like 'z' of length (coordinates) of one element. rest of 31 element length will be defined. so that in last deflection result would 10+z something like that so that when i put lenght z=10 i reflect in my result .

How would i do that

[madhan ravi]

https://in.mathworks.com/help/symbolic/syms.html