Question

[(a:7+69):9+71]:20+8=12

Answer 1

Răspuns: a = 84

Explicație pas cu pas:

[ ( a : 7 + 69 ) : 9 + 71 ] : 20 + 8 = 12

[ ( a : 7 + 69 ) : 9 + 71 ] : 20 = 12 - 8

[ ( a : 7 + 69 ) : 9 + 71 ] : 20 = 4

( a : 7 + 69 ) : 9 + 71 = 4 × 20

( a : 7 + 69 ) : 9 + 71 = 80

( a : 7 + 69 ) : 9 = 80 - 71

( a : 7 + 69 ) : 9 = 9

a : 7 + 69 = 9 × 9

a : 7 + 69 = 81

a : 7 = 81 - 69

a : 7 = 12

a = 12 × 7

a = 84 → numarul, aflat prin metoda mersului invers

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Verific:

[ ( 84 : 7 + 69) : 9 + 71] : 20 + 8 =12

= ( 81 : 9 + 71) : 20 + 8 =

= 80 : 20 + 8 =

= 4 + 8 =

= 12