2 × { 12 + 3 × [ 60 - 3 × ( 27 - 4 × 3 ) ] } - 5 x = 64
2 × { 12 + 3 × [ 60 - 3 × ( 27 - 12 ) ] } - 5 x = 64
2 × [ 12 + 3 × ( 60 - 3 × 15 ) ] - 5 x = 64
2 × ( 12 + 3 × 15 ) - 5 x = 64
2 × ( 12 + 45 ) - 5 x = 64
2 × 57 - 5 x = 64
114 - 5 x = 64
5 x = 114 - 64
5 x = 50
x = 50 : 5
x = 10 → numarul