Salut! :)
[ ( 1 + 2 ) × 7 + 56 ] : 7 × 3 =
( 3 × 7 + 56 ) : 7 × 3 =
( 21 + 56 ) : 7 × 3 =
77 : 7 × 3 =
11 × 3 = 33
•••
[ 1 + ( 2 × 7 + 56 : 7 ) ] × 3 =
[ 1 + ( 14 + 8 ) ] × 3 =
( 1 + 22 ) × 3 =
23 × 3 = 69
•••
[ ( 1 + 2 ) × 7 + 56 : 7 ] × 3 =
( 3 × 7 + 56 : 7 ) × 3 =
( 21 + 8 ) × 3 =
29 × 3 = 87