Răspuns :
Notez numarul cu x
( x - 8) : 2 + 18 = 24
( x - 8 ) : 2 = 24 - 18
( x - 8 ) : 2 = 6
x - 8 = 6 × 2
x - 8 = 12
x = 12 + 8
x = 20 → numarul, aflat prin metoda mersului invers
Verific: ( 20 - 8 ) : 2 + 18 = 12 : 2 + 18 = 6 + 18 = 24
( x - 8) : 2 + 18 = 24
( x - 8 ) : 2 = 24 - 18
( x - 8 ) : 2 = 6
x - 8 = 6 × 2
x - 8 = 12
x = 12 + 8
x = 20 → numarul, aflat prin metoda mersului invers
Verific: ( 20 - 8 ) : 2 + 18 = 12 : 2 + 18 = 6 + 18 = 24
(x - 8 ): 2 + 18 = 24
( x - 8 ) : 2 = 24 - 18
( x - 8 ) : 2 = 6
x - 8 = 6 × 2
x - 8 = 12
x = 12 + 8
x = 20
( x - 8 ) : 2 = 24 - 18
( x - 8 ) : 2 = 6
x - 8 = 6 × 2
x - 8 = 12
x = 12 + 8
x = 20