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    Having trouble working this out..

    Q - The fraction, (p), of an adults dose of medicine which should be given to a child who weighs, (w)kg, is given by the formula - p= 3w+20/200

    a. Use the formula to find the weight of a child wose dose is the same as an adult..

    Help..
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    (Original post by Bryz)
    Having trouble working this out..

    Q - The fraction, (p), of an adults dose of medicine which should be given to a child who weighs, (w)kg, is given by the formula - p= 3w+20/200

    a. Use the formula to find the weight of a child wose dose is the same as an adult..

    Help..
    So what fraction do you need if the doses are the same

    That gives you p

    Solve for w
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    (Original post by TenOfThem)
    So what fraction do you need if the doses are the same

    That gives you p

    Solve for w
    sorry, i still don't understand

    i am poor at maths..
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    (Original post by Bryz)
    sorry, i still don't understand

    i am poor at maths..
    P is the fraction

    If a child needed half an adult dose p would be 0.5

    The child needs a full adult dose, so what is p
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    (Original post by TenOfThem)
    P is the fraction

    If a child needed half an adult dose p would be 0.5

    The child needs a full adult dose, so what is p
    Just worked it out, thanks, p = 60

    BUT the next question, I was asked to make w the subject, and I am stuck halfway through it, could you please make w the subject so i can see where i am going wrong?
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    p= 3w+20/200

    Subtract 20/200 from both sides and divide by 3

    20/200 = 1/10 or 0.1
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    (Original post by L'Evil Fish)
    p= 3w+20/200

    Subtract 20/200 from both sides and divide by 3

    20/200 = 1/10 or 0.1
    Bit late mate Thanks anyways!

    BUT the next question, I was asked to make w the subject, and I am stuck halfway through it, could you please make w the subject so i can see where i am going wrong?
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    (Original post by Bryz)
    Bit late mate Thanks anyways!

    BUT the next question, I was asked to make w the subject, and I am stuck halfway through it, could you please make w the subject so i can see where i am going wrong?
    Can't see anything?
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    (Original post by L'Evil Fish)
    Can't see anything?
    What do you mean?

    I was asked to make (w) the subject of the original equation : p = 3w + 20/200

    I did most of it, but I am stuck on the last bit or have done it wrong, could you please do that with your working so I can see if I am correct/where I went wrong?
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    (Original post by Bryz)
    What do you mean?

    I was asked to make (w) the subject of the original equation : p = 3w + 20/200

    I did most of it, but I am stuck on the last bit or have done it wrong, could you please do that with your working so I can see if I am correct/where I went wrong?
    I told you
    Subtract 20/200 from both sides.
    Divide by 3.
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    (Original post by L'Evil Fish)
    I told you
    Subtract 20/200 from both sides.
    Divide by 3.
    How does that make sence?:O

    Could you show each step logically, and represent both sides please? Thanks

    Also the next question after that is to :

    Express A in terms of W in the following formula

    3w+20/200 = A/A+12
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    (Original post by Bryz)
    Just worked it out, thanks, p = 60

    BUT the next question, I was asked to make w the subject, and I am stuck halfway through it, could you please make w the subject so i can see where i am going wrong?
    No

    P does not equal 60

    Btw

    Your original post is VERY misleading

    You should have said p=(3w+20)/200
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    (Original post by Bryz)
    How does that make sence?
    It would make sense IF your OP had been correct

    But, as I say, it isn't
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    Start with w

    What do you do to w to get p

    Do the reverse to p to get w
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    (Original post by TenOfThem)
    No

    P does not equal 60

    Btw

    Your original post is VERY misleading

    You should have said p=(3w+20)/200
    :eek: no.wonder...
    (Original post by Bryz)
    How does that make sence?:O

    Could you show each step logically, and represent both sides please? Thanks

    Also the next question after that is to :

    Express A in terms of W in the following formula

    3w+20/200 = A/A+12
    The first:

    p = \frac{3w+20}{200}
    Multiply by 200 200p = 3w + 20

    Now subtract 20 from both sides and divide by 3.
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    (Original post by L'Evil Fish)
    :eek: no.wonder...


    The first:

    p = \frac{3w+20}{200}
    Multiply by 200 200p = 3w + 20

    Now subtract 20 from both sides and divide by 3.
    Thank you my friend!
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    (Original post by TenOfThem)
    No

    P does not equal 60

    Btw

    Your original post is VERY misleading

    You should have said p=(3w+20)/200
    Sorry!

    Could you guys show each step logically for this question? :

    Express A in terms of W in the following formula

    3w+20/200 = A/A+12
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    (Original post by Bryz)
    Sorry!

    Could you guys show each step logically for this question? :

    Express A in terms of W in the following formula

    3w+20/200 = A/A+12
    So, even though you are sorry, you are not willing to use the bracket keys to ask this question
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    (Original post by Bryz)
    Sorry!

    Could you guys show each step logically for this question? :

    Express A in terms of W in the following formula

    3w+20/200 = A/A+12
    Please please use brackets.

    (3w+20)/20 = A/(A+12)

    Make.a.common denominator? Or multiply throughout by 20(a+12)

    What do you get?
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    (Original post by TenOfThem)
    So, even though you are sorry, you are not willing to use the bracket keys to ask this question
    Ok, from now on I shall use brackets! That statement you made did make me chuckle though.
    (Original post by L'Evil Fish)
    Please please use brackets.

    (3w+20)/20 = A/(A+12)

    Make.a.common denominator? Or multiply throughout by 20(a+12)

    What do you get?
    You've lost me..
 
 
 
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