What if the answer to 30-[40 - (10-2) ]

First you would subtract 10-2 which you be 8

so you would have 30-[40 - (8) ].

Second you subtract 40 - (8) which would give you 32 so you would be left with 30-[32]

Lastly you would subtract 30-[32] which would give you - 2.

Your final answer would be - 2.