Calculeza respectand regulile invatatea)a) (7x7+7:7)x7
(20:2+28)x2
(18x2+18):6

b) 196-3x(89-45)
36x2x(12+47)
15+60:(39-29)

c) 1000-(35+60x2)+40
999+(10:2x4)-501
50+(40+80x100)-50

Va rog frumos raspuns rapid