# Solving a simple equation in SymPy.jl fails
**URL:** https://discourse.julialang.org/t/solving-a-simple-equation-in-sympy-jl-fails/11146
**Category:** Numerics
**Created:** [May 25, 2018, 1:53pm UTC](https://discourse.julialang.org/t/solving-a-simple-equation-in-sympy-jl-fails/11146 "2018-05-25T13:53:41Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@ufechner7](https://discourse.julialang.org/u/ufechner7)
#### Post date: [May 25, 2018, 1:53pm UTC](https://discourse.julialang.org/t/solving-a-simple-equation-in-sympy-jl-fails/11146/1 "2018-05-25T13:53:41Z")
Hello,
I tried to use SymPy.jl to solve a simple equation, but it fails. It eats more and more memory until the computer stalls.
Two questions:
a) where can I file a bug report?
b) how can I solve this equation in Julia?
```julia
using SymPy
@syms pressure_ground positive=true pressure_air positive=true temperature positive=true height positive=true
eqn = ((pressure_ground / pressure_air) ^ (1.0 / 5.257) - 1.0) * (temperature + 273.15) / 0.0065 - height
solve([eqn], [temperature])
```
---
### Author:  [@mzaffalon](https://discourse.julialang.org/u/mzaffalon)
#### Post date: [May 25, 2018, 2:53pm UTC](https://discourse.julialang.org/t/solving-a-simple-equation-in-sympy-jl-fails/11146/2 "2018-05-25T14:53:43Z")
I am not sure why it does not work with the numerical values. Symbolic algebra works fine:
```julia
pg, pa, t, h = symbols("pg, pa, t, h", positive=true)
α, T0, s = symbols("alpha, T0, s", positive=true)
eqn = ((pg / pa) ^ α - 1) * (t + T0) / s - h
solve(eqn, t)
```
---
### Author:  [@ufechner7](https://discourse.julialang.org/u/ufechner7)
#### Post date: [May 25, 2018, 7:11pm UTC](https://discourse.julialang.org/t/solving-a-simple-equation-in-sympy-jl-fails/11146/3 "2018-05-25T19:11:45Z")
Thanks a lot for your work-around!
Nevertheless its a bug that solving the original problem doesn’t work. I will investigate, if the same problem happens in Python, then I will do a bug report on SymPi.
---
### Author:  [@mzaffalon](https://discourse.julialang.org/u/mzaffalon)
#### Post date: [May 26, 2018, 9:08am UTC](https://discourse.julialang.org/t/solving-a-simple-equation-in-sympy-jl-fails/11146/4 "2018-05-26T09:08:01Z")
A MWE that shows a weird behaviour is the following:
```julia
using SymPy
t, s = symbols("t, s")
eqn = t / Sym("0.0065") - s
sol = solve(eqn, t)[1] # -> 0.00649999999999999⋅s
subs(eqn, t, sol) # -> -9.99200722162641e-16⋅s
```
It looks like divisions on non-integer numbers are performed as Float64 and then converted back into SymPy.Sym. Maybe you would like to look into this first?
---
### Author:  [@mzaffalon](https://discourse.julialang.org/u/mzaffalon)
#### Post date: [May 29, 2018, 9:02pm UTC](https://discourse.julialang.org/t/solving-a-simple-equation-in-sympy-jl-fails/11146/5 "2018-05-29T21:02:54Z")
I think it is a SymPy.jl bug.
[https://github.com/JuliaPy/SymPy.jl/issues/217](https://github.com/JuliaPy/SymPy.jl/issues/217)