Răspuns:
Explicație pas cu pas:
2 + b × 9 - 25 = 40
2 + b × 9 = 40 + 25
2 + b × 9 = 65
b × 9 = 65 - 2
b × 9 = 63
b = 63 : 9
b = 7
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36 - 42 : e : ( 15 : 3 - 4 : 1 ) - 20 = 10
36 - 42 : e : ( 5 - 4 ) = 10 + 20
42 : e : 1 = 36 - 30
42 : e = 6 × 1
e = 42 : 6
e = 7
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Răspuns: f = 9
Explicație pas cu pas:
11 - ( 7 × 5 - 9 × 9 : f : 3 ) : 8 = 7
( 35 - 81 : f : 3 ) : 8 = 11 - 7
( 35 - 81 : f : 3 ) : 8 = 4
35 - 81 : f : 3 = 4 × 8
81 : f : 3 = 35 - 32
81 : f : 3 = 3
81 : f = 3 × 3
f = 81 : 9
f = 9 → numarul, aflat prin metoda mersului invers
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( d × 4 + 20 ) : 4 = 12
d × 4 + 20 = 12 × 4
d × 4 = 48 - 20
d × 4 = 28
d = 28 : 4
d = 7
