MYTUTOR SUBJECT ANSWERS

500 views

Make x the subject of the equation y = {2(1+x)}/(3x+1)

This is an A* grade extension GCSE maths question on rearranging equations.

The question is asking us to find an equation that would represent x. In the question this x appears on the denominator (bottom half) and numerator (upper half). So the first thing we have to do is multiply out by the denominators to get rid of them. Lets do this one by one.

This gives:

y(3x-1) = 2(1+x)

To simplify the equation, we expand (multiply out) the bracket on the right hand side (RHS). Which gives us:

y (3x - 1) = 2 + 2x

Now we do the same thing to the left hand side (LHS):

3yx - y = 2 + 2x

Now, since we want x by itself, it is better to group x all together. So, we want to have the everything with x on the LHS and everything without an x on the RHS.

To do this, we'll have to add y to both sides and take away 2x on both sides to the above equation. 

3yx - y + y - 2x = 2 + 2x + y - 2x

As you can see, the positive and negatives will cancel and so this will give us:

3yx - 2x = y + 2

Excellent. Now we've made everything a lot simpler and makes it easy to answer the question. As you can see, x on the LHS is the common factor. So if we take out the x on the LHS like: 

x(3y - 2) = y + 2

we can see that to get x by itself, we will then need to divide both sides by 3y - 2 like so:

x(3y - 2)/(3y - 2) = y + 2/(3y - 2)

As you can see the (3y - 2) on the LHS will cancel and so this will give us:

x = (y + 2)/(3y - 2)

And there you have it!

Katrina G. GCSE Chemistry tutor, A Level Chemistry tutor, GCSE Maths ...

1 year ago

Answered by Katrina, a GCSE Maths tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

460 SUBJECT SPECIALISTS

£20 /hr

Laura L.

Degree: Chemistry (MCHEM) (Masters) - Warwick University

Subjects offered:Maths, Chemistry+ 1 more

Maths
Chemistry
Biology

“Hi there! I'm a third-year Chemistry student, I tutor maths from 11+ to A level as well as GCSE Science, A level Biology, and Chemistry”

£18 /hr

Juris B.

Degree: Computer Science (Bachelors) - St. Andrews University

Subjects offered:Maths, Computing

Maths
Computing

“I am a Computer Science at the University of St. Andrews. Before that however, I was a pupil in a school in the North-East of Scotland. With the combined passion and availability of superb teachers - I was given an opportunity to exce...”

£20 /hr

Eszter H.

Degree: Modern Languages (Bachelors) - Durham University

Subjects offered:Maths, History+ 6 more

Maths
History
German
English and World Literature
English Literature
English Language
.MLAT (Modern Languages)

“I am a Modern Languages (German and Spanish) student at Durham University. I believe that the knowledge of foreign languages is becoming more and more important, thus I am devoted to help every student who want to develop their German...”

About the author

£18 /hr

Katrina G.

Degree: Biochemical Engineering (Masters) - University College London University

Subjects offered:Maths, Science+ 1 more

Maths
Science
Chemistry

“About Me: I am a Biochemical Engineering student at University College London (UCL). I have always had a real passion and love for all things 'science' and 'maths'  and hope that my tutorials will instill that love in you, too. I am v...”

MyTutor guarantee

You may also like...

Other GCSE Maths questions

How to solve the maths GCSE question about Hannah's sweets that went viral

How do I expand (x+a)(x+b)? (plus example)

how do you find the original price of something that has been changed by a percentage decrease

The first four terms of an arithmetic sequence are: 3, 10, 17, 24. What is an expression, in terms of n, for the nth term?

View GCSE Maths tutors

We use cookies to improve your site experience. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok