Geometry

Input:nsolve(y+57+x+16+4x-5,x)

Intepretation:Solve $(y+57+x+16+4x-5=0)$ for $x$

$y+57+x+16+4x-5=0$

Merge the corresponding terms:

$y+5x+68=0$

Move $y$ and $68$ to the left:

$5x=-y-68$

Divide the entire function by a factor of 5:

$x=-\frac{1}{5}y-\frac{68}{5}$

$=\frac{1}{5}\left(-y-68\right)$

Q.E.D.