Maths Help :)

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My little brother isnt exactly the brightest math student and i have completely forgot how to help him with this problem.

2x - 8 < -13

He needs to know how to work it out so if you could help him that would be greatly appreciated.
 

Ciao

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x< -5/2

There you go.
 

Hipster Madara

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My little brother isnt exactly the brightest math student and i have completely forgot how to help him with this problem.

2x - 8 < -13

He needs to know how to work it out so if you could help him that would be greatly appreciated.
Are you serious?

Whatever.


2x - 8 < -13

1. 2x < -5
2. x < -2.5


Hope it's not wrong. >__>
 
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Um how the hell is -5/2 the same as 11? I understand that -2.5 is the same as the fraction but please do explain how 11=-2/5...
 

Iruka

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Um how the hell is -5/2 the same as 11? I understand that -2.5 is the same as the fraction but please do explain how 11=-2/5...

The answer is x < -2.5. The person who answered 11 was just being an ass.

The question is a basic inequality.
2x - 8 < -13
2x < -5
x < -5/2

Which can be expressed as a decimal:
x < -2.5
 
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Drizzy

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2x-8 < -13
What this is saying, is that 2x-8 is less than -13. The aim is to get 1x (or just x) on one side by itself.
2x < -13 + 8
What I did here, was move the -8 before the < sign, moving it across the sign makes it the opposite which is a positive (+) 8.
2x < -5
Here, all I did was simplify. Negative thirteen (-13) added to positive eight (+8) is negative five (-5).
2x/2 < -5/2
X is still not on it's own, that's 2x and not x there. To get only x, we must divide by a number that will leave only x. That number is two, because we do this to 2x, we must also divide the other side by 2 for it to be equal.
x < -2.5
2x divided by two is x, -5 divided by two is negative two and a half (-2.5)
 
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Hipster Madara

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2x-8 < -13
What this is saying, is that 2x-8 is less than -13. The aim is to get 1x (or just x) on one side by itself.
2x < -13 + 8
What I did here, was move the -8 before the < sign, moving it across the sign makes it the opposite which is a positive (+) 8.
2x < -5
Here, all I did was simplify. Negative thirteen (-13) added to positive eight (+8) is negative five (-5).
2x/2 < -5/2
X is still not on it's own, that's 2x and not x there. To get only x, we must divide by a number that will leave only x. That number is two, because we do this to 2x, we must also divide the other side by 2 for it to be equal.
x < -2.5
2x divided by two is x, -5 divided by two is negative two and a half (-2.5)

You did the same thing, just showed a mid-step for -13 + 8 and /2.
 
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Trollo Lucilfer

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2x - 8 < -13

2x < -13 + 8
2x < -5
1/2 * 2x > -5 * 1/2
x > -5/2
 
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King-Panda

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2x - 8 < -13


2x < -5

x < -2.5

I still remember this.... I am young, but last year gave tutoring sessions on maths and science to the year bellow!! business business!
 

Drizzy

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You did the same thing, just showed a mid-step for -13 + 8 and /2.

Ah, I was unsure since you skipped a few steps. He did say he wasn't sure how to do it, simplifying it would be best to do. ^^
 
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