3?2 • 4?3 = - 12?6
4?12 : 2?2 = - 2?6
15?6 : 3?2 = - 5 ?3
?28 - 10?7 = - -8 ?7
9?2 + 3?50 = - 24 ?2
2?50 + 6?2 = - 16?2
6?3 + ?75 = - 11?3
2/?7 = - (2?7)/7
1/?5 = - = ?5/5