Question

若x-y+2的绝对值与x+y-1的绝对值互为相反数,则xy的负倒数是

Answer 1

∵|x-y+2|与|x+y-1|为相反数

∴x-y+2=x+y-1=0

∴x=-1/2 y=3/2

∴xy=-3/4

∴xy负倒数为4/3