Thread: SAT Kaplan problem

or all numbers x and y, let the operation # be defined as x#y=x-xy. If a and b are positive integers, whuich can be equal to zero?

1) a#b
2) (a+b)#b
3) A # (a+b)


1 only
2 only
3 only
1 and 3
1 and 2

What have you tried?

Where are you stuck ??