Question

若a,b互为倒数,x,y互为相反数,且m的绝对值是3,解答下列各题

Answer 1

ab=1,x+y=0,|m|=3 m=3或-3

1:

2:5ab-m+x-4+y

=5*1-3-4

=-2

或

5ab-m+x-4+y

=5*1-（-3）-4

=4

3:5x-ab+5y

=5(x+y)-ab

=-1