98=?+8 64=60+? 12-9+6? 13-6-4?80-20-60?100-10-40?

Question

98=?+8 64=60+? 12-9+6? 13-6-4?80-20-60?100-10-40?

Comments

98+8=98

Answer 1

90+8=98
64=60+4
12-9+6=9
13-6-4=11
80-20-60=0
100-10-40=50

Answer 2

98=90+8,64=60+4,12-9+6=9,13-6-4=3,80-20-60=0,100-10-40=50