Tuesday

July 22, 2014

July 22, 2014

Posted by **Sarah** on Sunday, May 17, 2009 at 9:32am.

I'm sitting my maths non-calculator GCSE tomorrow and am currently revising. I'm doing a practise paper and am currently stuck on this question:

Express A in terms of w.

3w + 20 A

-------- = --------

200 A + 12

-- Can you explain to me step by step how to solve this problem? I'm really bad with understanding maths lingo btw :)

Thank you!

- Maths -
**Sarah**, Sunday, May 17, 2009 at 9:33amArg, that problem is supposed to be

3w + 20

-------

200

is equal to

A

----

A + 12

- Maths -
**Reiny**, Sunday, May 17, 2009 at 9:40amwrite it like this, it is easier to read in this format.

(3w+20)/200 = A/(A+12)

cross-multiply to get

(3w+20)(A+12) = 200A

3Aw + 36w + 20A + 240 = 200A

3Aw - 180A = -240 - 36w

switch all the signs

180A - 3Aw = 240 + 36w

factor out an A

A(180 - 3w) = 240 + 36w

divide by 180 - 3w

A = (240+36w)/(180-3w)

A = (80+12w)/(60-w)

**Related Questions**

Maths - Hi, I am just doing some maths revision in light of my maths GCSE resit...

very complicated maths - Hey guys, need some help with a question ive been stuck...

MATHS&SCIENCE - Do I qualify for an application for a Sasol bbursary as I am ...

maths - You are asked to write a program for the course calculator to help a ...

MATHS&SIENCE - Do I qualify for an application for a Sasol bbursary as I am ...

Chemistry - Hey; I'm currently in a kinetics class and I am trying to do a ...

maths, variations - question: if y is proportional to x, and that y=6 when x=12...

English - Hello. Will you please help me with one more question? Is it possible ...

Healthcare Communication Strategies - I am trying to write a paper on ...

Maths Revision - Does anyone know of any websites where I might be able to find ...