answer:22
step by step:
so we have PE(MD)(AS)
(for multiplication and division it depends on left to right, same for addition and subtraction)
this could be read as
30 - [(12/3)*2]
first you would do 12/3 which is 4
then you do 4*2 which is 8
last you do 30-8 which is 22
hope that helps :)