化解求值—2(ab-3a^2)-[2b ^2-(5ab+a ^2)+2ab],a.b满足|a+1|+|2b-a|=0要详解,急··_数学解答

化解求值—2(ab-3a^2)-[2b ^2-(5ab+a ^2)+2ab],a.b满足|a+1|+|2b-a|=0
要详解,急····

人气：412 ℃　时间：2020-03-31 19:08:14

解答

绝对值非负所以a+1=02b-a=0解出a=-1,b=-1/2代数式=-2ab+6a²-[2b²-5ab-a²+2ab]=-2ab+6a²-2b²+a²+3ab=7a²-2b²+ab=7a²-b(2b-a)代入=7+0=7