og12 math

zjqadele

125. If ° represents one of the operations +, –, and ×,

is k ° (L + m) = (k ° L ) + (k ° m) for all numbers k,L,

and m ?

(1) k ° 1 is not equal to 1 ° k for some numbers k.(2) ° represents subtraction.

The anwser is each statement alone is sufficient.
My question is how can K-(L+M) = 2K - (L+M) is for ALL numbers K, L and M?????

zjqadele

I c. thanks.

Leliolevine

LZ 被绕进去了。。本题是问条件能否判断 k ° (L + m) = (k ° L ) + (k ° m)对所有的k l m都成立，（1）（2）条件都是。是减法运算，能判断出 k ° (L + m) = (k ° L ) + (k ° m) is not for all k l m

serenashu

做的时候也选的D，没考虑太仔细。现在也很困惑~~求指点~~