Respuesta :

Steps:
18 x 2
What is that?
You can also think of it as 9 x 4 if that is easier
Then whatever you got for that, add 21 then subtract 12 and add 1

answer

54

explanation

21+18×2-12+1 (21-12+1=9)

9+18×2(9+18=27)

27×2(27×2=54)

54(answer)