Question 46230
 
  {{{-6(2^2-(3+4))+3}}}
= {{{-6(4-7)+3}}}   =  {{{-24+42+3}}}
= 21  Answer. 

First take out the innermost brackets by simplifying it.  Then take out the bracket by multiplying.(applying distributive law).  Then simplify and you get the answer.  Understood?

gsm