Răspuns :
[ ( x + 4 ) x 4 ] : 4 + 4 x 4 + 4 = 29
[ ( x + 4 ) x 4 ] : 4 + 16 + 4 = 29
[ ( x + 4 ) x 4 ] : 4 + 20 = 29
[ ( x + 4 ) x 4 ] : 4 = 29 - 20
[ ( x + 4 ) x 4 ] : 4 = 9
( x + 4 ) x 4 = 9 x4
( x + 4 ) x 4 = 36
x + 4 = 36 : 4
x + 4 = 9
x = 9 - 4
x = 5
[ ( x + 4 ) x 4 ] : 4 + 16 + 4 = 29
[ ( x + 4 ) x 4 ] : 4 + 20 = 29
[ ( x + 4 ) x 4 ] : 4 = 29 - 20
[ ( x + 4 ) x 4 ] : 4 = 9
( x + 4 ) x 4 = 9 x4
( x + 4 ) x 4 = 36
x + 4 = 36 : 4
x + 4 = 9
x = 9 - 4
x = 5
7.
b)
[(x+4)*4+4]:4+4*4+4=29
[(x+4)*4+4]:4+16+4=29
[(x+4)*4+4]:4+16=29-4
[(x+4)*4+4]:4+16=25
[(x+4)*4+4]:4=25-16
[(x+4)*4+4]:4=9
(x+4)*4+4=9*4
(x+4)*4+4=36
(x+4)*4=36-4
(x+4)*4=32
x+4=32:4
x+4=8
x=8-4
x=4
b)
[(x+4)*4+4]:4+4*4+4=29
[(x+4)*4+4]:4+16+4=29
[(x+4)*4+4]:4+16=29-4
[(x+4)*4+4]:4+16=25
[(x+4)*4+4]:4=25-16
[(x+4)*4+4]:4=9
(x+4)*4+4=9*4
(x+4)*4+4=36
(x+4)*4=36-4
(x+4)*4=32
x+4=32:4
x+4=8
x=8-4
x=4