# Math Help - unfamiliar symbols

1. ## unfamiliar symbols

For all numbers a and b, let be defined by . For all numbers x, y, and z, which of the following must be true?

I.
II.
III.

• A. I only
• B. II only
• C. III only
• D. I and II only
• E. I, II, and III

2. Originally Posted by aeroflix
For all numbers a and b, let be defined by . For all numbers x, y, and z, which of the following must be true?

I.
II.
III.

• A. I only
• B. II only
• C. III only
• D. I and II only
• E. I, II, and III
you just have to convert each side of the equation to see if it's true ...

$x \odot y = xy + x + y$

$y\odot x = yx + y + x$

since $xy+x+y = yx+y+x$ for all real numbers, statement I is true.

now check the other two ...