Algebra Watch

fliss1992
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Here goes:

I have a question that I'm not sure of the answer, here is how I've worked it out and the answer I have..

x/9 = 2

The answer I got for x is 33?

I worked it out like this..

x/9 x 3 = 2 x 3 9 x 3 = 27 2 x 3 = 6

27 + 6 = 33

I think this is wrong, if so can somebody show me how I went wrong.

I also have another question, but don't have a clue how to work it out..

72/x^3 - 9 = 1

Thanks
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m4ths/maths247
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Is 33 divided by 9 equal to 2?
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Ché.
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(Original post by m4ths/maths247)
Is 33 divided by 9 equal to 2?
Yeah?
Is it?
You've actually confused me on how you cannot grasp the basic algebraic concepts/laws...

What really confused you on that question in particular?

There is no point moving on to the second problem if you can't independently solve the ones of equivalent basic level.

PRACTICE!


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m4ths/maths247
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(Original post by Ché.)
Yeah?
Is it?
You've actually confused me on how you cannot grasp the basic algebraic concepts/laws...

What really confused you on that question in particular?

There is no point moving on to the second problem if you can't independently solve the ones of equivalent basic level.

PRACTICE!


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I am a little lost.
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fliss1992
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no it's not equal to two, I never said the question was right, in fact I said it was wrong in my eyes!

I have the answer as 22 for the equations..
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1144297
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(Original post by fliss1992)
Here goes:

I have a question that I'm not sure of the answer, here is how I've worked it out and the answer I have..

x/9 = 2

The answer I got for x is 33?

I worked it out like this..

x/9 x 3 = 2 x 3 9 x 3 = 27 2 x 3 = 6

27 + 6 = 33

I think this is wrong, if so can somebody show me how I went wrong.

I also have another question, but don't have a clue how to work it out..

72/x^3 - 9 = 1

Thanks
Hi!

I looked over your working, and I do not quite understand why you did what you did. I assume that you understand that you multiply both sides (x/9 x 3 = 2 x 3) however then you sail off and do the wrong thing.

Firstly, you could have just multiplied each side by 9, (as you move it across) and got (x*9)/9 = 2*9, and the 9/9 would cancel and leave x = 18. But, just to avoid confusion, I will go over your way.

You start with multiplying them by 3, which would work, but you multiply 9 - you would multiply the x on top, to get (3x/9)=(2*3), which simplified to be (x/3) = 6. From this you can just do 3*6 to get 18, which matches the original. We can check our working by putting our value (18) into the original formula.

18/2 = 9.

Which works.

As for the second problem, while I will not work it out for you, you can use the same rules. Remember BIDMAS (Brackets, Indices, Divide, Multiply, Add, Subject) as your order, and just to be sure, when
a/b=x
then
a/x=b
ie, 1/3=x, 1/x=3

With them rules, it should be quite easy to solve the second. If you need any more help, just say.

Good luck!

Ten People (ThatPerson2)
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m4ths/maths247
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(Original post by fliss1992)
no it's not equal to two, I never said the question was right, in fact I said it was wrong in my eyes!

I have the answer as 22 for the equations..
When I asked that question I am asking it to allow you to build understanding.
When solving an equation the final step is to check if the value you have found 'satisfies' the equation. (ie it works, or its right).

Taking your question:
Some number is divided by 9 to give 2
What is the opposite (or inverse) of dividing?

Solving equations in these case is carrying out inverse operations.
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QuantumSuicide
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Dis guy must be trolling. Surely.

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fliss1992
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the opposite to divide is times, but I don't know where I'm meant to do that?
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fliss1992
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who's trolling?
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m4ths/maths247
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(Original post by QuantumSuicide)
Dis guy must be trolling. Surely.

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With less than 60% of students obtaining C grades or higher in GCSEs nationally I am not suprised people may struggle with this.
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m4ths/maths247
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(Original post by fliss1992)
the opposite to divide is times, but I don't know where I'm meant to do that?
Right, start here:
https://www.youtube.com/watch?v=Rb6n22UjAKY

Then:
https://www.youtube.com/watch?v=1OEMSfr1cvQ
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QuantumSuicide
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(Original post by m4ths/maths247)
With less than 60% of students obtaining C grades or higher in GCSEs nationally I am not suprised people may struggle with this.
That's a bit surprising yo. Where did you get that statistic from?
I apologise to da OP if you weren't trolling, my friend.

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m4ths/maths247
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(Original post by QuantumSuicide)
That's a bit surprising yo. Where did you get that statistic from?
I apologise to da OP if you weren't trolling, my friend.

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National stats.
Its about 56% each year who get a C or higher.
Many different reasons for the 44% not getting there.
Fair play to the OP for signing up to a forum and looking for help. The questions do seem troll like for able mathematicians but far from troll like when you actually meet kids on a daily basis.
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james22
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(Original post by fliss1992)
no it's not equal to two, I never said the question was right, in fact I said it was wrong in my eyes!

I have the answer as 22 for the equations..
Can you post the original question please?
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Mr M
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(Original post by james22)
Can you post the original question please?
The question was:

Solve \displaystyle \frac{x}{9}=2

Nothing to see here James. Move along.
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james22
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(Original post by Mr M)
The question was:

Solve \displaystyle \frac{x}{9}=2

Nothing to see here James. Move along.
His second post suggested that the actual question was different, since 22 doesn't solve it either (the answer he was apparntly given).
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Toastyy
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x/9 = 2
x = 2 x 9
x = 18
It is really that simple
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Toastyy
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(Original post by Toastyy)
x/9 = 2
x = 2 x 9
x = 18
It is really that simple
Guys this is the awnser, you can plug it in and you will get two o.e
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Mr M
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(Original post by james22)
His second post suggested that the actual question was different, since 22 doesn't solve it either (the answer he was apparntly given).
Take my advice unless you want to get sucked into the quagmire.
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