I don’t understand that why written as minus b_out divide w_out[0] and in one lines down. Because we don’t that while writting code of the decision boundary, we do not do division. Someone please explanation to me… (Also I am sorry for my bad English :)))

The code for x0 and x1 is some algebra that gives two points where the value of the prediction would be exactly 0.5. Which is also equivalent to where (x*w + b) = 0.

Then it just draws a straight line between them.

Thank you my question to answer. Well why is there division?

If you plug in some values for w and solve for x, you need to divide.

Hmm okay. Stupid me. I was knowing that but my head confused. Very thanks my friend. Greeting from Turkeys