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Solving Simultaneous Equations – O Level Additional Mathematics

learn simultaneous equations for o level add math

Get our simultaneous equations free course based on the Singapore additional Math syllabus right now! This course consists of 3 video lectures and 1 worksheet (with complete worked solutions). Become good at simultaneous equations in just 4 short lessons.

Simultaneous equations are often a part of a question in A Math. You can solve simultaneous equations in any chapter in A Math. Hence, it is important to know this chapter well.

In the O Level A Maths syllabus, you are tested on solving simultaneous equations in two variables by substitution, with one of the equations being a linear equation. While solving simultaneous equations by substitution will solve almost all questions, I also share how to solve the equations by the elimination method. Sometimes, solving simultaneous equations using the elimination method may be easier, so I highly recommend knowing them as well. In fact, when you are in primary school, you have actually solved questions using the elimination method. Did you know that?  Find out in our free course below!

Introduction to Simultaneous Equations

Firstly, why do we need to solve simultaneous equations? In this video, you’ll learn what are simultaneous equations and why do we need to solve them.

I also go through the 2 methods used for solving simultaneous equations – the substitution method and elimination method.

Solving Simultaneous Equations by Substitution

You can solve almost all simultaneous equations using the substitution method. In this video, you will learn how to solve both linear and non-linear simultaneous equations. For A Maths at O level, you are expected to solve simultaneous equations in two variables by substitution, with (at least) one of the equations being a linear equation (i.e. the other equation can be a non-linear one).


You can solve simultaneous equations by substitution in a systematic manner. You can do this by following the 5 general steps which I’ve summarized below:

steps on how to solve simultaneous equations by substitution method for o level add math

Watch this video here to learn how to apply these steps:

Solving Simultaneous Equations by Elimination Method

In this video, you will learn how to solve simultaneous equations by elimination. While you can solve almost all questions with substitution, there are times when using this method is easier.

I also share that you had used this method when you were in primary school. Watch it to find out!

Solve the Simultaneous Equations Yourself

Want to do well in Maths? Then you’ve got to practice! In lesson 4, you will be doing the worksheet. I’ve included complete worked solutions in the worksheet.

Download the worksheet below and start doing it!

(p/s: The worksheet is free, just put $0 and you can download it for free. No credit card or PayPal information required.)

Simultaneous Equations and Quadratic Functions

Learning how to solve simultaneous equations is only a part of the chapter on quadratic functions tested in the O Level Additional Mathematics syllabus. We have created an entire course on quadratic functions based on the Singapore O Level Additional Mathematics Syllabus.
In this course, I not only go through more about simultaneous equations (some tricks on how to solve them easily by observation), but I also talk about other topics tested in the quadratic function chapter. These are:

  • Finding the maximum or minimum value of a quadratic function using the method of completing the square
  • Conditions for quadratic function to be always positive or negative
  • Using discriminant to determine conditions for a quadratic equation to have: (i) two real roots (ii) two equal roots (iii) no real roots
  • Using discriminant to determine related conditions for a given line to: (i) intersect a given curve (ii) be a tangent to a given curve (iii) not intersect a given curve •
  • Solving simultaneous equations in two variables by substitution, with one of the equations being a linear equation
  • Solving quadratic inequalities, and representing the solution on the number line

I also go through many common questions you’ll see in your O Level exams in detail, so that you are equipped with the skills on how to solve these questions when you sit for your O Level Additional Mathematics exam.

This course is the full tuition lessons on quadratic function that I conduct for my students taking the O Level Add Math. This topic is big, and it usually takes two 2- hour lessons to complete. Now, you have the opportunity to watch the entire class on-demand, anytime you like, and re-watch it as many times as you want. 

Do check out our course here:

course on quadratic functions tested in O level additional mathematics

All these courses are hosted on the Udemy platform, which offers 30- day money-back guarantee (terms and conditions apply see here). So what are you waiting for?

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