Respuesta :

Brackets first:
4 + 1 = 5
5 - 5 = 0

Division next:
18/3 = 6

Answer = 6

18/3 (5-4+1) subtract 5 -4 then add it with 1

1+1=2

18/3 divide by3  6 x 2 = 12

The answer is 12