The answer you are looking for is -891.
Solution/Explanation:
Writing out the expression first
-2-7{3+4[(-5)²+6]}
Simplifying (-5)², which is 25, since (-5)(-5)=25
-2-7[3+4(25+6)]
Simplifying 25+6, which is 31
-2-7[3+4(31)]
Simplifying 4(31), which is 124
-2-7(3+124)
Simplifying 3+124, which is 127
-2-7(127)
Simplifying -7(127), which is -889
-2-889
Finally, you will get -891.
So, therefore, the final answer to this problem is -891.
Hope this helped answer your question for you. Good day to you.