Where do two lines meet?

You will find the crossing point of $a_1 x + b_1 y = c_1$ and $a_2 x + b_2 y = c_2$ with one short formula, then the program draws both lines and the point.

The idea. Eliminating each variable in turn gives, with $d = a_1 b_2 - a_2 b_1$,

When $d = 0$, the lines do not cross at one point.

Your tasks.

1. In d_value, return $a_1 b_2 - a_2 b_1$.
2. In meet, return the point (x, y), or None when $d = 0$.
3. Set point to where $3x + 4y = 26$ and $2x - y = 10$ meet.