Question

已知a、b互为相反数,c、d互为倒数,x的绝对值是2,求a+b/3+(a+b-cd)x-5cd的值

Answer 1

a+b=0

c*d=1

x=±2

a+b/3+(a+b-cd)x-5cd

=0/3+(0-1)*(±2)-5*1

=0±2-5

=-3或-7