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 in the video
Solve the simultaneous equations:
[latex]x + y = 3[/latex]
Example 2
Example in the video
Solve the simultaneous equations:
[latex]2x + y = 2[/latex]