Răspuns :
Răspuns:
Explicație pas cu pas:
13 - 3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } + 7 = 20
13 - 3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 20 - 7
3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 13 - 13
2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] = 0 : 3
12 : [ 10 - 8 : ( a + 3 ) × 2 ] = 2 - 0
10 - 8 : ( a + 3 ) × 2 = 12 : 2
10 - 8 : ( a + 3 ) × 2 = 6
8 : ( a + 3 ) × 2 = 10 - 6
8 : ( a + 3 ) = 4 : 2
8 : ( a + 3 ) = 2
a + 3 = 8 : 2
a + 3 = 4
a = 4 - 3
a = 1 → numarul,aflat prin metoda mersului invers
13 - 3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } + 7 = 20
13 - 3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 20 - 7
13 - 3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 13
3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 13 - 13
3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 0
{ 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 0 : 3
{ 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 0
{ 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 2 - 0
{ 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 2
[ 10 - 8 : ( a + 3 ) × 2 ] = 12 : 2
[ 10 - 8 : ( a + 3 ) × 2 ] = 6
[ 8 : ( a + 3 ) × 2 ] = 10 - 6
[ 8 : ( a + 3 ) × 2 ] = 4
[ 8 : ( a + 3 ) ] = 4 : 2
[ 8 : ( a + 3 ) ] = 2
a + 3 = 8 : 2
a + 3 = 4
a = 4 - 3
a = 1
Verificare :
13 - 3 × { 2 - 12 : [ 10 - 8 : ( 1 + 3 ) × 2 ] } + 7 =
13 - 3 × [ 2 - 12 : ( 10 - 8 : 4 × 2 ) ] + 7 =
13 - 3 × [ 2 - 12 : ( 10 - 2 × 2 ) ] + 7 =
13 - 3 × [ 2 - 12 : ( 10 - 4 ) ] + 7 =
13 - 3 × ( 2 - 12 : 6 ) + 7 =
13 - 3 × ( 2 - 2 ) + 7 =
13 - 3 × 0 + 7 =
13 - 0 + 7 =
13 + 7 = 20
13 - 3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 20 - 7
13 - 3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 13
3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 13 - 13
3 × { 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 0
{ 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 0 : 3
{ 2 - 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 0
{ 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 2 - 0
{ 12 : [ 10 - 8 : ( a + 3 ) × 2 ] } = 2
[ 10 - 8 : ( a + 3 ) × 2 ] = 12 : 2
[ 10 - 8 : ( a + 3 ) × 2 ] = 6
[ 8 : ( a + 3 ) × 2 ] = 10 - 6
[ 8 : ( a + 3 ) × 2 ] = 4
[ 8 : ( a + 3 ) ] = 4 : 2
[ 8 : ( a + 3 ) ] = 2
a + 3 = 8 : 2
a + 3 = 4
a = 4 - 3
a = 1
Verificare :
13 - 3 × { 2 - 12 : [ 10 - 8 : ( 1 + 3 ) × 2 ] } + 7 =
13 - 3 × [ 2 - 12 : ( 10 - 8 : 4 × 2 ) ] + 7 =
13 - 3 × [ 2 - 12 : ( 10 - 2 × 2 ) ] + 7 =
13 - 3 × [ 2 - 12 : ( 10 - 4 ) ] + 7 =
13 - 3 × ( 2 - 12 : 6 ) + 7 =
13 - 3 × ( 2 - 2 ) + 7 =
13 - 3 × 0 + 7 =
13 - 0 + 7 =
13 + 7 = 20