# Maxima eliminate with ugly _SAGE_VAR_

Why I got those ugly `_SAGE_VAR_u`

and `_SAGE_VAR_x`

instead of straight `u`

and `x`

?
I am using SageMath 8.9.

```
var('x, t, u')
maxima.eliminate([x == -((t*(1 + 2*t))/(1 + 4*t^5)), u == -((2*t)/(1 + t^2))],[t])
```

```
[(17*_SAGE_VAR_u^5-40*_SAGE_VAR_u^4+160*_SAGE_VAR_u^2-128)*_SAGE_VAR_x^2+(4*_SAGE_VAR_u^5+46*_SAGE_VAR_u^4-56*_SAGE_VAR_u^3-64*_SAGE_VAR_u^2+64*_SAGE_VAR_u)*_SAGE_VAR_x+5*_SAGE_VAR_u^5-4*_SAGE_VAR_u^4]
```

How do I get rid off it? Substituting does not seem to work.

**Update:**

Eliminating without maxima - why it does not wok?

```
R.<x,t,u> = PolynomialRing(QQ)
gens = [x == -((t*(1 + 2*t))/(1 + 4*t^5)), u == -((2*t)/(1 + t^2))]
J = R.ideal(gens)
J.elimination_ideal([t])
```

```
Ideal (0) of Multivariate Polynomial Ring in x, t, u over Rational Field
```

While this works:

```
R.<x,y,z> = PolynomialRing(QQ)
gens = [ x^2 + y^2 + z^2 - 14, x*y + y*z + z*x -11, x*y*z - y^2 -2]
J = R.ideal(gens)
J.elimination_ideal([x,y])
```

```
Ideal (z^12 + 2*z^11 - 25*z^10 - 40*z^9 + 329*z^8 - 4*z^7 - 1763*z^6 + 3984*z^5 + 2475*z^4 - 43722*z^3 + 75942*z^2 - 60588*z + 23409) of Multivariate Polynomial Ring in x, y, z over Rational Field
```

You can just convert back to sage using

`.sage()`

method on the result. And your sage is very obsolete.Thanks, this could be an answer. Yes I know, but I have not in plan to install Linux to use the latest version, I heard it slows down Windows after installation of Windows Subsystem for Linux and Linux.

@FrédéricC: I edited my question... maybe you can answer also the update.

Since the

`Cygwin`

version of Sage is no longer maintained, you cut yourself of Sage advances (which are interesting...).You may need to add RAM to your system. And possibly check the hearsays...

An alternative is to install Linux in a double boot installation, then use your Windows partition in a virtual machine. This works at least with

`Virtualbox`

, and may be doable with`qemu`

.