# Unexpected solve() errors

```
#Area [m^2]
Ab = 0.00313659226
#CB Ratio
cb = 0.262
eng4 =[solve(cb == Vc/(Ab*Lb),Lb) for Vc in xrange(0.000001,0.00002)]
print(eng4)
```

This returns an empty list [] and I have no idea why. And this one:

```
#Ideal Gas Law[Relates Pressure and Volume]
#Definitions v3
#Main Tank Pressure[Pascals]
Pp=1013529.32
#Tank Volume[m^3]
Vt=0.0013929
#Moles of Air
#Gas Constant
r=8.3144621
#Ambient Temperature[Kelvin][70F]
t= 294.261
eng5= solve(Pp*Vt == n*r*t,n,solution_dict=1)
v3=eng5[0]
v4=n(v3)
n(v4)
```

__main__:18: DeprecationWarning: Substitution using function-call syntax and unnamed arguments is deprecated and will be removed from a future release of Sage; you can use named arguments instead, like EXPR(x=..., y=...) See http://trac.sagemath.org/5930 for details. 75589949342674/131001015929725

Or it just shows the fraction. It's been acting weird lately

Why?