如果[a+b]的平方与2a-b-3的绝对值是互为相反数,那么ab=?........................................................................................................................................................................................................................................................................................................
问题描述：
如果[a+b]的平方与2a-b-3的绝对值是互为相反数,那么ab=?
........................................................................................................................................................................................................................................................................................................
答
[a+b]的平方与2a-b-3的绝对值是互为相反数，
a+b=0
2a-b-3=0
3a=3
a=1
b=-1
ab==-1
答
如果[a+b]的平方与2a-b-3的绝对值是互为相反数,
即[a+b]的平方+|2a-b-3|=0
a+b=0
2a-b-3=0
解方程组得
a=1,b=-1
那么ab=-1