need help with a weird question (math) | Mathematics | Page 1

polar plover Dec 18, 2022, 10:21 PM

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i was wondering lets say (x - 8) is the 8 a negative number even when the 8 is like this (- 8) and not like this (-8)

late nightBOT Dec 18, 2022, 10:21 PM

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polar plover Dec 18, 2022, 10:25 PM

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help pls

trim pumice Dec 18, 2022, 10:26 PM

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-8 is a negative number, 8 is a positive number
you can consider that expression to be an addition of x plus (-8) or a substraction of x minus 8

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¯_(ツ)_/¯

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Pick whichever interpretation is most convenient for you at any given time

polar plover Dec 18, 2022, 10:28 PM

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.close

late nightBOT Dec 18, 2022, 10:28 PM

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Solved

Post marked as solved by @polar plover.

Use .unsolved if this was a mistake.

trim pumice Dec 18, 2022, 10:32 PM

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Subtraction is a made up thing anyway :P_ _

polar plover Dec 18, 2022, 10:32 PM

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trim pumice Subtraction is a made up thing anyway :P_ _

yes

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can u help me again

trim pumice Dec 18, 2022, 10:33 PM

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go on

polar plover Dec 18, 2022, 10:33 PM

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is this question right
3(x - 4) ≤ 4x - 8 is the answer 0,75x ≤ x - 1

trim pumice Dec 18, 2022, 10:34 PM

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How'd you arrive there?

polar plover Dec 18, 2022, 10:35 PM

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i first removed the -4 with adding 4 then i needed to add 4 on the -8

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then it was 3x ≤ 4x - 4

trim pumice Dec 18, 2022, 10:35 PM

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Watch your parenthesis

polar plover Dec 18, 2022, 10:35 PM

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?

trim pumice Dec 18, 2022, 10:36 PM

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3(x-4) =/= 3x -4

polar plover Dec 18, 2022, 10:36 PM

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yes

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after i did +4 it was only 3(x) on the right side

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so its 3x

trim pumice Dec 18, 2022, 10:37 PM

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3(x-4)+4 =/= 3x-4+4

polar plover Dec 18, 2022, 10:37 PM

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then i divided everything ( 3x ≤ 4x - 4) with 4

polar plover Dec 18, 2022, 10:37 PM

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trim pumice 3(x-4)+4 =/= 3x-4+4

yes like that

trim pumice Dec 18, 2022, 10:37 PM

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I should clarify I'm taking =/= to mean "not equal to"

polar plover Dec 18, 2022, 10:37 PM

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oooooh

trim pumice Dec 18, 2022, 10:37 PM

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as opposed to = "equal to"

polar plover Dec 18, 2022, 10:38 PM

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so what do i need to do?

trim pumice Dec 18, 2022, 10:38 PM

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Distributive property

polar plover Dec 18, 2022, 10:38 PM

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where did everything go wrong?

trim pumice Dec 18, 2022, 10:38 PM

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trim pumice 3(x-4) =/= 3x -4

This step

polar plover Dec 18, 2022, 10:38 PM

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but i wanted to remove the -4 so cant i just add 4

trim pumice Dec 18, 2022, 10:39 PM

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We have to start from the beginning

polar plover Dec 18, 2022, 10:39 PM

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ok lets do it

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this the question 3(x - 4) ≤ 4x - 8

trim pumice Dec 18, 2022, 10:39 PM

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How much is 3(x-4)

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simplify it

polar plover Dec 18, 2022, 10:40 PM

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3 times x and 3 times -4 ?

trim pumice Dec 18, 2022, 10:40 PM

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correct, so that is...

polar plover Dec 18, 2022, 10:40 PM

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3x - 12

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?

trim pumice Dec 18, 2022, 10:40 PM

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Yes, so 3(x-4) = 3x-12

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Add four on both sides

polar plover Dec 18, 2022, 10:41 PM

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3x-12+4 = 3x -8

trim pumice Dec 18, 2022, 10:41 PM

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See where the problem was?

polar plover Dec 18, 2022, 10:41 PM

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yes i noticed

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ok ill try the question again

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so 3x-12 ≤ 4x -8 then i do +8 on both sides so it becomes 3x-4 ≤ 4x

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now idk what to do more

trim pumice Dec 18, 2022, 10:43 PM

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you can subtract 3x from both sides

polar plover Dec 18, 2022, 10:43 PM

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oh i can?

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so then -4 ≤ x

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?

trim pumice Dec 18, 2022, 10:44 PM

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yep

trim pumice Dec 18, 2022, 10:44 PM

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polar plover oh i can?

the only thing you have to watch out for in inequations is multiplying or dividing both sides by a negative number

polar plover Dec 18, 2022, 10:45 PM

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trim pumice the only thing you have to watch out for in inequations is multiplying or dividi...

yes

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well thank u very much 😄 ❤️

#need help with a weird question (math)