Question

I need help with making examples I don't know what to do for that.

You must create a lesson that teaches another student how to solve the following inequality: –x + 3 > 7.
Your main mission for this activity is to provide a detailed answer to the question below.

Why must you flip the inequality symbol when you divide by a negative number?

You know that if the symbol is not flipped you will end up with a false statement, but why is that so? Research and brainstorm (with your partner if you chose to do this collaboratively) to come up with this answer. Remember, you are teaching this to another student, so you must include detailed explanations, visuals, and at least two additional examples. You may submit your lesson in a word document, power point presentation, use audio/video tools, etc.

In order to solve –x + 3 > 7 you would first want to add x to both sides which would give you 3 > 7 + x. Then you would subtract 7 from both sides, doing that should give you the final product of -4 > x. The only thing you want to be careful of is when you multiply or divide by a negative number. However you can avoid this making sure the coefficient of the variable is positive. That is why we added x on the first step. You could have started by subtracting 3 to both sides and getting –x > 4 but then you would have to change the sign to get x so you have to change the inequality as well and ge

Answer 1

I just need help coming up with the examples I am not sure what to do for that

Answer 2

In order to solve –x + 3 > 7 you would first want to add x to both sides which would give you 3 > 7 + x. Then you would subtract 7 from both sides, doing that should give you the final product of -4 > x. The only thing you want to be careful of is when you multiply or divide by a negative number. However you can avoid this making sure the coefficient of the variable is positive. That is why we added x on the first step. You could have started by subtracting 3 to both sides and getting –x > 4 but then you would have to change the sign to get x so you have to change the inequality as well and get x < -4. So the answer is X < -4.

Answer 3

That is how I would explain it but how should I show examples?

Answer 4

Wow thank you

Answer 5

@k142 That is not a very nice thing to say.

Answer 6

@k142 you do not have to be a jerk about it I am a student and I am trying to learn

Answer 7

I told my opinion about that.

Answer 8

Okay, let's start with the inequality –x + 3 > 7

Answer 9

I came on here for help not for criticism

Answer 10

Thank you @heretohelpalways

Answer 11

instead of getting rid of the x, cancel out the 3 by subtracting 3 from both sides

Answer 12

to get −x>4

Answer 13

then divide both sides by -1

Answer 14

to get x<−4

Answer 15

Ok hang on a sec

Answer 16

you are supposed to get x by itself, instead of getting rid of it

Answer 17

let's try another inequality

Answer 18

In order to solve –x + 3 > 7 you would first want to subtract 3 from both sides which would give you -x > 4. Then you would divide both sides by -1. By doing that should give you the final product of x < -4. The only thing you want to be careful of is when you multiply or divide by a negative number. However you can avoid this making sure the coefficient of the variable is positive. That is why we added x on the first step. You could have started by subtracting 3 to both sides and getting –x > 4 but then you would have to change the sign to get x so you have to change the inequality as well and get x < -4. So the answer is X < -4.

Answer 19

Am I correct up until adding x on the first step

Answer 20

The answer is correct though right?

Answer 21

this might help: http://math.stackexchange.com/questions/94790/why-do-we-reverse-inequality-sign-when-dividing-by-negative-number

Answer 22

Wait please help me

Answer 23

okay , don't worry.I am still here

Answer 24

Does that explanation at least look right?

Answer 25

Wouldn't adding x to -x cancel out the variable

Answer 26

the main question/point is "Why must you flip the inequality symbol when you divide by a negative number?"

Answer 27

In order to solve –x + 3 > 7 you would first want to subtract 3 from both sides which would give you -x > 4. Then you would divide both sides by -1. By doing that should give you the final product of x < -4. The only thing you want to be careful of is when you multiply or divide by a negative number. However you can avoid this making sure the coefficient of the variable is positive. We started by subtracting 3 from both sides and got –x > 4 then you have to change the sign to get x < -4. So the answer is x < -4.

Answer 28

so try answering " Why must you flip the inequality symbol when you divide by a negative number?" Then, explain that question in your paragraph, instead of telling them how to avoid the situation

Answer 29

Ok so I am confused by what I read?

Answer 30

this also might help you understand the question: http://mathforum.org/library/drmath/view/53287.html

Answer 31

Ok

Answer 32

Now I am getting confused. I'll tag some people @Skielerlucas04

Answer 33

unless you understand it now?

Answer 34

@Michele_Laino

Answer 35

Multiplying it by -1 is like reversing gravity, so that things fall
up, and the heavier object is now pulled more strongly up rather than
down. If you do that, the scale will reverse:

Answer 36

But what about dividing it?

Answer 37

@heretohelpalways The inequality sign changes because you are switching the signs of the values in the inequality. So you must flip the inequality sign as well. Once all values become negative, that means that negatives are flipped from one side to the other (or abolished, if both sides were negative). If the sign is not flipped, it makes the solution a whole different range of numbers, because it changes the inequality.

Answer 38

So now explain that inside of your paragraph while explaining how to solve the inequality

Answer 39

In order to solve –x + 3 > 7 you would first subtract 3 from both sides which would give you -x > 4. Then you would divide both sides by -1. By doing that should give you the final product of x < -4. The only thing you want to be careful of is when you multiply or divide by a negative number. Multiplying or dividing it by -1 is like reversing gravity, so that things fall up, and the heavier object is now pulled more strongly up rather than down. If you do that, the scale will reverse. The inequality sign changes because you are switching the signs of the values in the inequality. So you must flip the inequality sign as well. Once all values become negative, that means that negatives are flipped from one side to the other (or cancelled out, if both sides were negative). If the sign is not flipped, it makes the solution a whole different range of numbers, because it changes the inequality. However you can avoid this making sure the coefficient of the variable is positive. We started by subtracting 3 from both sides and got –x > 4 then you have to change the sign to get x < -4. So the answer is x < -4.

Answer 40

How is that?

Answer 41

But I still lack the examples