## ajprincess 2 years ago Please help:) What does this mean? $$\exists x, y \in Z \ni d=ax+by$$

1. wio

Well $$\mathbb{Z}$$ means integers... that is ... -3, -2, -1, 0, 1, 2, 3, ...

2. ajprincess

ya actually I want to knw what the symbol $$\ni$$ means?

3. wio

So you're saying there exist the integers x, and y, where if you multiply by a and b, you end up with another integer.

4. wio

It's just "in this set"

5. wio

and "in the integer set" basically means "is an integer"

6. wio

The $$\exists$$ symbol means that the number/thingy exists.

7. wio

and it satisfies whatever equation/properties/etc follow

8. ajprincess

So that means there exist integers x and y such that ax+by=d is also an integer. Am I right?@wio

9. wio

I would translate that expression to say: "There exists two integers, $$x$$ and $$y$$, such that $$ax+by$$ is an integer.

10. wio

@ajprincess Yeah. I think the $$d$$ is just there for the sake of saying the result is an integer.

11. ajprincess

oh k. thanx a lot:)