✏ 54 : 2 + 2 x [ ( 3 x 25 - 4 x 18 : 9 + 3 x 11 ) : 4 ] =
= 27 + 2 x [ ( 75 - 72 : 9 + 33 ) : 4 ] =
= 27 + 2 x [ ( 75 - 8 + 33 ) : 4 ] =
= 27 + 2 x [ ( 67 + 33 ) : 4 ] =
= 27 + 2 x ( 100 : 4 ) =
= 27 + 2 x 25 =
= 27 + 50 =
= 77 ✔