Which expression describes the set of numbers given by the interval:

A

Step-by-step explanation:

Looking at the interval, we can see that this includes all of the numbers coming from negative infinity all the way up to -1.

In other words, the set being described here are all the numbers less than or equal to -1.

Another way to write this is all numbers no more than -1.

Thus, our answer is A.

And we're done!

answer: c.  

step-by-step explanation:

mixtures containing substances that get attracted to magnet can be separated using a magnet. we can separate iron from a mixture of sand and iron, as only iron attracts to the magnet.