MYTUTOR SUBJECT ANSWERS

391 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 ...

11 months ago

Answered by Katrina, a GCSE Maths tutor with MyTutor


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

456 SUBJECT SPECIALISTS

£18 /hr

Laura K.

Degree: Chemical Engineering (Masters) - Bath University

Subjects offered: Maths, Science+ 3 more

Maths
Science
Physics
Further Mathematics
Chemistry

“Hey there! I am Laura and I am currently studying Chemical Engineering at University of Bath. I am really passionate about Science and I am willing to share my knowledge through tutoring you. My passion and expertise in science can be...”

£18 /hr

Sarah M.

Degree: Biochemistry (Bachelors) - Birmingham University

Subjects offered: Maths, Science+ 2 more

Maths
Science
Chemistry
Biology

“I am a final year Biochemistry student at the University of Birmingham. I have a passion for science and hope to inspire others through teaching; I’m currently applying to become a chemistry teacher. I believe all students have the ab...”

£18 /hr

Sahil M.

Degree: Medicine (Bachelors) - Manchester University

Subjects offered: Maths, Spanish+ 3 more

Maths
Spanish
Chemistry
Biology
-Medical School Preparation-

“Hello! My name is Sahil and I am currently a medical student at the University of Manchester. I am really looking forward to tutoring you in Spanish, Chemistry, Biology or Maths as well as trying to help you during the difficult proce...”

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

What is Pythagorus' Theorem?

How do you work out the area of a triangle?

Sasha has a bag containing 12 red beads, and 8 blue beads. She draws one bead from the bag at random. What is the probability that it is blue?

What's the difference between a histogram and a bar chart?

View GCSE Maths tutors

Cookies:

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

mtw:mercury1:status:ok