7 Rezolvă, după model:
(24 : 6) + (30 : 6) = (24 +30) : 6 = 54 :6 = 9

a) (25:5) + (15:5) =
(40 : 8) + (32: 8) =

b) (42 : 7) + (14 : 7) =
(16:4) + (24 : 4) = ​