Question

Which of the following expressions shows how to rewrite 7 − 8 using the additive inverse and displays the expression correctly on a number line?
@mathstudent55

Answer 1

Do you know what the additive inverse is?

Answer 2

um not really :( srry

Answer 3

Additive inverses are numbers that add up to zero.

Answer 4

oh ok

Answer 5

That is the definition.
Here is the practical way to know it.
The additive inverse of zero is zero since 0 + 0 = 0

Answer 6

ok

Answer 7

With all other numbers, the additive inverse of a number is just take the number and change the sign.

Answer 8

The additive inverse of 2 is -2.
The additive inverse of -1/2 is 1/2
The additive inverse of 7.18 is -7.18

Answer 9

Ok so far?

Answer 10

yes:)

Answer 11

Good.
When you deal with subtraction, you can define subtraction as adding the additive inverse.

Answer 12

That means any subtraction can be treated as an addition, but what you must do is change the number you are subtracting into its additive inverse.

Answer 13

For example, change 8 - 2 into an addition.
Answer: 8 - 2 = 8 + (-2)

Answer 14

oh ok

Answer 15

The example above was the subtraction 8 - 2.
The number 2 needs to be subtracted from the number 8.
We change the subtraction into an addition by changing the minus sign into a plus sign AND we change the 2 into the additive inverse of 2, which is -2.

Answer 16

ok

Answer 17

Now look at your example.
You have the subtraction 7 - 8
To change the subtraction into an addition, you keep the 7.
Change the - to +
Then change the 7 to its additive inverse which is -7

Answer 18

Try it and show me what you get.

Answer 19

ok

Answer 20

ummm... is it -8+7?

Answer 21

is that the answer?

Answer 22

helloooooo???

Answer 23

7 - 8
Keep the 7 as is:
7
Change the - into a +
7 +
Chang ethe 8 into its additive inverse: -8
7 + (-8)

Answer 24

7 + (-8) is the same as -8 + 7

Answer 25

Do you have choices?

Answer 26

yes

Answer 27

oh wait no

Answer 28

so whats the final answer?

Answer 29

I say it's 7 + (-8)

Answer 30

thanks :)

Answer 31

can you help me with more?

Answer 32

yes, one more, then i have to go.

Answer 33

ok