Modulo with negative numbers

Question

Can someone explain why these 2 lines in code give different results

https://code.sololearn.com/ctGo1AQLJ1Vr/?ref=app

Answer 1

6%-4 = 2 because
6/-4 = -1 + R/-4
R = 6 - (-1*-4) = 6 - (+4) = 2

-6%4 = -2 because
-6/4 = -1 + R/4
R = -6 - (-1*4) = -6 - (-4) = -2