23-a-{10a-[(5a-15)-(4-6a)]}
23-a-{10a-[(5a-15)-(4-6a)]}
试证明代数式-(a-23)-{10a-[5a-15-(4-6a)]}
(a+3a+5a+...+2009a)-(2a+4a+6a+...+2008a)=
(a+3a+ 5a+```+2007a)-(2a+4a+6a+```+2008a)=?
(a+3a+5a+...+2013a)-(2a+4a+6a+...+2012a)=
计算(a+3a+5a+.+2003a)-(2a+4a+6a+...+2004a)
(a+3a+5a+.+2003a)-(2a+4a+6a+.+2004a)
化简; a-2a+3a-4a+5a-6a+``````-2006a+2007a.
1+2a+3a^2+4a^3+5a^4+6a^5+5a^6+4a^7+3a^82a^9+a^10
快 2a-10/9-6a+a²÷(a²-25)*3a²+15a/5-a
计算a-2a+3a-4a+5a-6a+...+99a-100a.要过程
计算:(a+3a+5a+...+2013a)-(2a+4a+6a+..+2012a)=?