Răspuns :
[( a :5 ) x 2] : 4 + 5 = 9
[( a : 5 ) x 2 ] : 4 = 9 - 5
[ ( a : 5 ) x 2 ] : 4 = 4
( a : 5 ) x 2 = 4 x 4
a : 5 x 2 = 16
a : 5 = 16 : 2
a : 5 = 8
a = 8 x 5
a = 40
[( a : 5 ) x 2 ] : 4 = 9 - 5
[ ( a : 5 ) x 2 ] : 4 = 4
( a : 5 ) x 2 = 4 x 4
a : 5 x 2 = 16
a : 5 = 16 : 2
a : 5 = 8
a = 8 x 5
a = 40
[( a :5 ) x 2] : 4 + 5 = 9
[( a : 5 ) x 2 ] : 4 = 9 - 5
[ ( a : 5 ) x 2 ] : 4 = 4
( a : 5 ) x 2 = 4 x 4
a : 5 x 2 = 16
a : 5 = 16 : 2
a : 5 = 8
a = 8 x 5
a = 4
[( a : 5 ) x 2 ] : 4 = 9 - 5
[ ( a : 5 ) x 2 ] : 4 = 4
( a : 5 ) x 2 = 4 x 4
a : 5 x 2 = 16
a : 5 = 16 : 2
a : 5 = 8
a = 8 x 5
a = 4