解析 a,b互为相反数,则a+b=0
|c|与|d|互为相反数,则c=d=0
|x|=1,则有x=±1
于是:当x=1时
a + b/x +x + cd = a + b + 1 + 0 = 1
当x=-1时
a + b/x +x + cd = a - b - 1 + 0 = 2a -1
解析 a,b互为相反数,则a+b=0
|c|与|d|互为相反数,则c=d=0
|x|=1,则有x=±1
于是:当x=1时
a + b/x +x + cd = a + b + 1 + 0 = 1
当x=-1时
a + b/x +x + cd = a - b - 1 + 0 = 2a -1