solve this equation y=-1/2x if the domain is {-2, -1, 0, 1, 2}
What i get is that you have to plug in the numbers, but how do
i present the answer?? Please help!

Yes, plug in the numbers, and give the range:

The domain is {-2, -1, 0, 1, 2}

The range is gotten by plugging those in:

The range is {1, 1/2, 0, -1/2, -1}

That's my guess as to how to present the answer,
i.e., give the domain.

Edwin