1. Solve by elimination
  2. Same x terms
  3. Same y terms but opposite signs
  4. Same y terms but both signs are negative
  5. Same y terms but both signs are positive
  6. Neither x term nor y term are the same
  7. Substitution methods (Quadratic SImultaneous)

Introduction

This is an introduction to solving simultaneous equations by the method of elimination.

x terms are the same

In the next example only the x terms are the same.

y terms the same but with opposite signs

In this example the two equations have the same y terms but with opposite signs.

Care must be taken over the signs as mistakes can easily be made.

y terms are the same and both signs are negative

In this example the y terms are exactly the same and both signs are negative.

Care must be taken over the signs as mistakes can easily be made.

y terms are the same and both signs are positive

In this example the y terms are exactly the same and both signs are positive.

Neither the x or y terms are the same

In this example neither the x or y terms are the same so an adjustment needs to be made.


In these tutorials you are shown how to solve a simultaneous equation by the substitution method. You are also shown how it relates to the intersection of two graphs and why there are two sets of solutions.

Example 1

Example 2