calculeaza respectand regulile învățate

Răspuns:
a)99-45:(6+3)+36
==>99-45:9+36
99-5+36
94+36=130
b)84:4×(72:9+5×5)-54:6
21×(8+25)-9
21×33-9
=693-9=684
c)(7+9)×(81:9)
16×9==>144