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Metoda mersului invers​

Metoda Mersului Invers class=

Răspuns :

Răspuns:

a)

2 • (7 + x : 3) = 21 - 1

2 • (7 + x : 3) = 20

7 + x : 3 = 10

x : 3 = 3

x = 9

b)

2 • (7 + 84 : x) = 98

7 + 84 : x = 49

84 : x = 42

x = 2

c)

[2 • (7 + x : 3) + 9] : 5 = 5

2 • (7 + x : 3) + 9 = 25

2 • (7 + x : 3) = 16

7 + x : 3 = 8

x : 3 = 1

x = 3

d)

(3000 - x) : 3 + 74 = 400

(3000 - x) : 3 = 326

3000 - x = 978

x = 3000 - 978

x = 2022