a - a : 5 = 40
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a=?
a : 5 |---|
a |---|---|---|---|---| notam cele 6 segmente cu parte (p) iar apoi inlocuim
4 x p = 40
p = 40 : 4
p = 10
p = a : 5
a : 5 = 10
a = 10 x 5
a = 50
Verificare:
a - a : 5 = 40
50 - 50 : 5 = 40
50 - 10 = 40
40 = 40
