### Task:
Your job is to take a pair of parametric equations, passed in as strings, and convert them into a single rectangular equation by eliminating the parameter. Both parametric halves will represent linear equations of x as a function of time and y as a function of time respectively. 
The format of the final equation must be `Ax + By = C` or `Ax - By = C` where A and B must be positive and A, B, and C are integers. The final equation also needs to have the lowest possible whole coefficients. Omit coefficients equal to one.
The method is called `para_to_rect` or `EquationsManager.paraToRect` and takes in two strings in the form `x = at +(or -) b` and `y = ct +(or -) d` respectively, where `a` and `c` must be integers, and `b` and `d` must be positive integers. If `a` or `c` is omitted, the coefficient of _t_ is obviously assumed to be 1 (see final case in the example tests). There will NEVER be double signs in the equations inputted (For example: `"x = -12t + -18"` and `"y = -12t - -18"` won't show up.)
### Examples:
```python
para_to_rect("x = 12t + 18", "y = 8t + 7") => "2x - 3y = 15"
```
> __CALCULATION:__  
  x = 12t + 18  
  y = 8t + 7  
  2x = 24t + 36  
  3y = 24t + 21  
  2x - 3y = (24t + 36) - (24t + 21)  
  2x - 3y = 15  
```python
para_to_rect("x = -12t - 18", "y = 8t + 7") => "2x + 3y = -15"
```
> __CALCULATION:__  
  x = -12t - 18  
  y = 8t + 7  
  2x = -24t - 36  
  3y = 24t + 21  
  2x + 3y = (-24t - 36) + (24t + 21)  
  2x + 3y = -15  
```python
para_to_rect("x = -t + 12", "y = 12t - 1") => "12x + y = 143"
```
> __CALCULATION:__  
  x = -t + 12  
  y = 12t - 1  
  12x = -12t + 144  
  y   = 12t  - 1  
  12x + y = 143  
More examples in the sample test cases.
### Notes:
As you can see above, sometimes you'll need to add the two parametric equations after multiplying by the necessary values; sometimes you'll need to subtract them – just get rid of the _t_!
import re
from math import gcd

def para_to_rect(eqn1, eqn2):
    eqn1, eqn2 = [re.sub(r'\bt', '1t', e) for e in [eqn1, eqn2]]
    (a,b), (c,d) = ([[int(x.replace(' ', '')) for x in re.findall('-?\d+|[-+] \d+', e)] for e in [eqn1, eqn2]])
    x = c*b - a*d
    g = gcd(gcd(c, a), x)
    if c < 0:
        g = -g
    c, a, x = c//g, a//g, x//g
    return re.sub(r'\b1([xy])', r'\1', f'{c}x {"+-"[a > 0]} {abs(a)}y = {x}')
import re
from math import gcd

def para_to_rect(eqn1, eqn2):
    eqn1, eqn2 = [re.sub(r'\bt', '1t', e) for e in [eqn1, eqn2]]
    (a,b), (c,d) = ([[int(x.replace(' ', '')) for x in re.findall('-?\d+|[-+] \d+', e)] for e in [eqn1, eqn2]])
    x = c*b - a*d
    g = gcd(gcd(c, a), x)
    if c < 0:
        g = -g
    c, a, x = c//g, a//g, x//g
    return re.sub(r'\b1([xy])', r'\1', f'{c}x {"+-"[a > 0]} {abs(a)}y = {x}')