1. Parentheses are preceded by a "+". Remove the brackets and the "+"in front of them, and the symbols of the items in brackets remain unchanged.
There is a "-"before the brackets. Remove the brackets and the "-"sign in front, and change the symbols in brackets.
For example: -(a5[ power ]-6b)-(7+3b)
=-a^5+6b-7-3b
How about I'm on control education?
It is still possible to copy education from Confucius. Shangkong teaching and research team consists of ba