A number is prime if it is divisible by only itself and one. Thus, if a number is divisible by anything else, it can't be prime. Of the answer choices, only 427 isn't prime, because it is divisible by 7.

To figure out which number is prime, one strategy you could employ is using your calculator and dividing each choice by 3, 7, 9, 11, and 13. Because all of the answer choices are odd, we know none of them will be divisible by 2, 4, 6, 8, or 10. Also, none of them have a 0 or 5 in the ones place, so they can't be divisible by 5. Thus, the best numbers to try would be 3, 7, 9, 11, and 13. When you divide 427 by 7, you will get a whole number. For all the other answer choices, when you divide by 3, 7, 9, 11, and 13, you will never get a whole number.

The answer is 427.

Recall that the product of a negative number and a positive number is a negative number. Thus, we know that our answer will be a negative number. We then consider the product of the numbers, ignoring the sign. We know that . Then, we have that our final answer is .

The word product indicates multiplication. Thus, we remember that when we multiply a positive number by a negative number we get a negative number.

We know that dividing a positive integer and a negative integer will give us a negative integer. We thus consider the numbers themselves, without the sign.

Add a negative sign to find our answer is .

First multiply according to order of operations to get 6xy, and then see if there are like terms to be combined. In this case, there are not so the simplest form is

First multiply all the numbers .

If there is an even amount of negative signs, then the product will be positive. If there is an odd amount of negative signs, then the product will be negative.

Therefore, the answer is .

In this case, it is key to recall the rules for multiplying or dividing with negative values.

Negative * Positive = Negative

Negative * Negative = Positive

Positive * Positive = Positive

In this case, we are multiplying two negative numbers; thus the answer should be a positive number. To find the value, we can simply multiply the terms without their negatives.