The set {0, 1} is closed under which operation? (Points : 3)
addition
multiplication
subtraction
none of the above

Question

The set {0, 1} is closed under which operation? (Points : 3)
       addition
       multiplication
       subtraction
       none of the above

swissgirl · Answer

A set is closed under a certain operation if by using that operation on all members in the set results in only members of the set
Multiplication:
0*0=0
0*1=1
1*1=0
Addition:
0+0=0
0+1=1
1+1=2
Subtraction:
0-0=0
0-1=-1
1-1=0
1-0=1

So which operation would you think this set is closed for?

anonymous · Answer

multiplication

swissgirl · Answer

Yup

anonymous · Answer

could you help me with another?

swissgirl · Answer

Sure

anonymous · Answer

Which expression is greater than -|-0.4|?
(Points : 3)
       |-(-0.4)|

       -(-(-0.4))

       -|-(-0.4)|

       -|-0.4|

swissgirl · Answer

Ok lets start with -|-.4|
-|-.4|=-.4

anonymous · Answer

i know that -|-.4| is -.4

swissgirl · Answer

|-(-.4)|=|.4|=.4

anonymous · Answer

the next one would be -.4 right @swissgirl