因为(x+y-1)的平方与4丨x+3丨互为相反数,
所以x+y-1=0
x+3=0
解得：x=-3,y=4
x的y次方-xymn
=（-3）^4-(-3)*4mn
=81+12mn
=81+12
=93
已知(x+y-1)的平方与4丨x+3丨互为相反数,m,n互为倒数求x的y次方-xymn的值
因为(x+y-1)的平方与4丨x+3丨互为相反数,
所以x+y-1=0
x+3=0
解得：x=-3,y=4
x的y次方-xymn
=（-3）^4-(-3)*4mn
=81+12mn
=81+12
=93