SOLUTION: If the operation x*y is defined by x *y=(x+1)(y+1)-1, then which one of the following is false? (A) x * y = y * x for all real x and y. (B) x * (y + z) = (x * y) + (x * z) for

Algebra ->  Finance -> SOLUTION: If the operation x*y is defined by x *y=(x+1)(y+1)-1, then which one of the following is false? (A) x * y = y * x for all real x and y. (B) x * (y + z) = (x * y) + (x * z) for       Log On


   

Question 1064766: If the operation x*y is defined by x *y=(x+1)(y+1)-1, then which one of the following is false?
(A) x * y = y * x for all real x and y.
(B) x * (y + z) = (x * y) + (x * z) for all real x, y, and z.
(C) (x - 1) * (x + 1) = (x * x) - 1 for all real x.
(D) x * 0 = x for all real x.
(E) x * (y * z) = (x * y) * z for all real x, y, and z.
Found 2 solutions by Fombitz, ikleyn:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
x%2A0=%28x%2B1%29%280%2B1%29-1=%28x%2B1%29%281%29=x%2B1
So at least this one is false.

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
(D) x * 0 = x for all real x.


    x * 0 = (x+1)*(0+1)-1 = x+1-1 = x.


Exactly THIS ONE is TRUE.