How to solve an equation when the variable is in the denominator?

I find the best way to explain maths is by using more numbers than words, so I'll use an example to explain this:

3 - 2x+2/x+4 = 4

A good thing to do before attempting to solve an equation is to get rid of any denominators you have, in this case x+4

To do this we can multiply the fraction (2x+2/x+4) by (x+4) and both (x+4) would cancel each other out, leaving us with 2x+2!

However, this is an equation, which means that anything you change to one side of the = sign you have to do the same on the other side, to keep everything equal and balanced.

Another important thing to remember is that we will be multiplying (x+4) not x and 4, so I find it easier to put some brackets around them so we don't forget what we're doing. Now enough words, let's use the numbers to demonstrate what I mean:

3 - 2x+2/x+4 = 4

(x+4) x 3  +  (x+4) x -(2x+2/x+4)  =  (x+4) x 4

3x + 12 - (2x + 2) = 4x + 16

3x + 12 - 2x - 2 = 4x + 16

x + 10 = 4x + 16

x - 4x = 16 - 10

-3x = 6

x = -2

GD
Answered by G D. Maths tutor

5122 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Marcin buys 7 rulers and 15 crayons for £7. A ruler costs 12p more than a crayon. Find the cost of one crayon.


The number of uniform spherical balls that can be produced from a given mass of lead is inversely proportional to the radius of the ball cubed. If 2744 balls can be made when the radius is 1mm, how many balls can be made when the radius is 1.4mm ?


Simplify x^2 - 9x + 20


What can I say about the roots of a quadratic equation without actually calculating them?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences