Yes I indeed have a question. I get confused on diving the pairs and finding the answer. I need a breakdown on how to do it. Please and thankyou.

When you divide a negative number by another negative number the answer is positive. -54/-6 = -9 When you divide a positive number by another positive number the answer is positive. 54/6 = 9 When you divide a positive number by a negative number the answer is negative. 54/-6 = -9 When you divide a negative number by a positive number the answer is negative. -54/6 = -9 Hope this helps! (pls vote up)

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Course: 7th grade (Eureka Math/EngageNY) > Unit 2

Lesson 2: Topic B: Multiplication and division of integers and rational numbers

Multiplying two negative numbers

Google Classroom

If 3(-8) can be 3 equal groups of -8, what does -3(-8) mean? What does it mean to multiply any two negative numbers? Let's use the distributive property and other properties of multiplication to find out.

When we multiply a positive number times a negative number, the product is the opposite of the product of the absolute values of the numbers. This means the result is always negative.

But what about when we multiply a negative number times a negative number? Let’s explore this idea using three different methods, starting with the distributive property.

Multiplication with the distributive property: negative times negative

The distributive property works the same with negative numbers as with positive numbers and

0

. Let's use it to see what happens when we multiply two negative numbers, starting with the example

- 7 (- 3)

Before we do, make a prediction.

What do you predict will be the value of $- 7 (- 3)$ ‍?
This is an ungraded prediction, because we learn more when we make a guess before we get feedback.

Now let's use the zero-product property and the distributive property to reason about the product.

Fill each blank with a number to keep both sides of the equation equivalent.


$- 7 ($ ‍ Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍ $)$ ‍	$=$ ‍	$0$ ‍
$- 7 (- 3 +$ ‍ Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍ $)$ ‍	$=$ ‍	$0$ ‍
$- 7 (- 3) + (- 7) (3)$ ‍	$=$ ‍	$0$ ‍
$- 7 (- 3) + (- 21)$ ‍	$=$ ‍	$0$ ‍
Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍ $+ (- 21)$ ‍	$=$ ‍	$0$ ‍

Multiplication by a negative as repeated subtraction from $0$ ‍

Number lines

As a general trend, the symbol "

-

" changes the direction we move on a number line, whether we interpret it as a negative sign or a subtraction symbol.

Match the number lines to the expressions they represent.
Duplicate graphs will match to either equivalent expression.

1

Evaluate each expression.


$2 (4)$ ‍	$=$ ‍	Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
$- 2 (4)$ ‍	$=$ ‍	Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
$- 2 (- 4)$ ‍	$=$ ‍	Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍

Equal groups of objects

We represent multiplying by a positive number by adding equal groups of objects. We represent multiplying by a negative number by subtracting equal groups of objects.

- 2 (- 5)

is the value we have left after we take away

2

groups of

- 5

objects. But how do we subtract groups of objects when we don't have any?

We can start with zero-pairs. The following diagram represents

0

because there are

10

positive integer chips and

10

negative integer chips.

Now we can take away

2

groups of

- 5

Evaluate.

- 2 (- 5) =

Conclusion

Now that we have explored multiplying a negative number times a negative number using three different methods, what conclusions can we draw?

Describe a general pattern for when we multiply two negative numbers.

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jordan.adams
Posted 7 months ago. Direct link to jordan.adams's post “Yes I indeed have a quest...”
Yes I indeed have a question. I get confused on diving the pairs and finding the answer. I need a breakdown on how to do it. Please and thankyou.
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(2 votes)
Answer
- kookie
  Posted 5 months ago. Direct link to kookie's post “When you divide a negativ...”
  When you divide a negative number by another negative number the answer is positive. -54/-6 = -9
  
  When you divide a positive number by another positive number the answer is positive. 54/6 = 9
  
  When you divide a positive number by a negative number the answer is negative. 54/-6 = -9
  
  When you divide a negative number by a positive number the answer is negative. -54/6 = -9
  
  Hope this helps!
  (pls vote up)
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  (4 votes)
AISLYNNR
Posted 5 months ago. Direct link to AISLYNNR's post “- x - = +”
- x - = +
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(2 votes)
Answer
Juan Mejía
Posted 4 months ago. Direct link to Juan Mejía's post “In short: If two signs ar...”
In short: If two signs are the same, the result will be always positive. In contrast, if the two signs are different, the result will be always negative. This way you only have to multiply the numbers as you'd normally do (without taking in account the sign) and then prefix the sign to the result as same as i exposed before.
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(2 votes)
Answer
gabriellegalindon
Posted 3 months ago. Direct link to gabriellegalindon's post “I understand this much mo...”
I understand this much more than his videos, this is only grade 7 math but kinda thanks for teacher Sal( did I get his name right)
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(2 votes)
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- AliK
  Posted 3 months ago. Direct link to AliK's post “yeah his name is Sal Khan...”
  yeah his name is Sal Khan.
  Comment on AliK's post “yeah his name is Sal Khan...”
  (1 vote)
kimberlyn67
Posted 8 months ago. Direct link to kimberlyn67's post “Normally, whenever two ne...”
Normally, whenever two negative numbers decide to meet, the two negatives (- times -) decide to mash together to make a (+)
One negative stays same while the other turns side ways .
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(1 vote)
Answer
nathan.christopher787
Posted 23 days ago. Direct link to nathan.christopher787's post “It was helpful for me to ...”
It was helpful for me to apply a symmetry to the equations -7(3) and -7(-3) by adding a 0 to the beginning. Originally, I had thought -7(-3)=-7-(-7)-(-7) and the negatives weren't adding up correctly, until I thought to add the zero to the beginning, then it all clicked. That is, -7(3)=0+(-7)+(-7)+(-7) and -7(-3)=0-(-7)-(-7)-(-7). Then I read the explanation of -7(-3)= -(-7)-(-7)-(-7) and it made more sense to me.
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(1 vote)
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moses
Posted 6 months ago. Direct link to moses's post “Hi, My Name is Moses kauf...”
Hi, My Name is Moses kaufman
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(1 vote)
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- moses
  Posted 6 months ago. Direct link to moses's post “yes it is Moses Kaufman”
  yes it is Moses Kaufman
  Comment on moses's post “yes it is Moses Kaufman”
  (1 vote)
29keltaher
Posted 8 months ago. Direct link to 29keltaher's post “Find the answer for -3(-5...”
Find the answer for -3(-5)
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(0 votes)
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- avery.pendergraft29
  Posted 8 months ago. Direct link to avery.pendergraft29's post “its 15”
  its 15
  Comment on avery.pendergraft29's post “its 15”
  (3 votes)
Leyton
Posted 8 months ago. Direct link to Leyton's post “when you multiply two neg...”
when you multiply two negative #sthe product will come out as positive. For example, -2(-45) will be 90
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(0 votes)
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davidz10000
Posted 6 months ago. Direct link to davidz10000's post “For the integer chips pro...”
For the integer chips problem, you can easily add integer chips to nothing by simply adding a positive integer chips to 0. However, how can you remove negative integer chips from nothing?
Well, it says you have to take away 2 groups of negative 5 integer chips. Of course, you can't just have 5 negative integer chips so you have to derive those 5 negative integer chips from: NOTHING! What is a number that we can use to represent that you have nothing: 0! :). So you can just use 10 positive integer chips and 10 negative integer chips to represent zero and take out the 2 groups of negative 5 integer chips. This will leave you with 10 positive integer chips remaining. So positive 10 is your answer.
-2(-5)=10.
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7th grade (Eureka Math/EngageNY)