Читать книгу Algebra I All-in-One For Dummies - Mary Jane Sterling, Mary Sterling Jane - Страница 55

What role does 0 play in the signed-number show? What does 0 do to the signs of the answers? Well, when you’re doing addition or subtraction, what 0 does depends on where it is in the problem. When you multiply or divide, 0 tends to just wipe out the numbers and leave you with nothing.

Here are some general guidelines about 0:

 Adding zero: is just a. Zero doesn’t change the value of a. (This is also true for .)

 Subtracting zero: When doing subtraction with 0, order matters. Is 0 being subtracted or are you subtracting from 0?. When you subtract 0 from a number, you don’t change it.. Use the rule for subtracting signed numbers: Change the operation from subtraction to addition and change the sign of the second number, giving you .

 Multiplying by 0: . Twice nothing is nothing; three times nothing is nothing; multiply by nothing and you get nothing; likewise, .

 Dividing 0 by a number: . Take you and your friends: If none of you has anything, dividing that nothing into shares just means that each share has nothing.Note: You can’t use 0 as a divisor. Numbers can’t be divided by 0; not even 0 can be divided by 0. The answers just don’t exist.

So, working with 0 isn’t too tricky. You follow normal addition and subtraction rules, and just keep in mind that multiplying and dividing with 0 (0 being divided) leaves you with nothing — literally.

Q. Perform the operation:

A. . Adding 0 to any number doesn’t change the number – even when the number is negative!

Q. Perform the operations:

A. 0. You want to pay attention to the whole problem. The first operations result in a huge number, but the final result is 0. That’s what 0 does best!

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