Simultaneous equations part two

Something to know about equations is that you can multiply them by a number and you still have the same equation.

I mean, if you have the equation and you multiply it by to get then this isn’t really a new equation. It gives the same information as the original equation.

This is just a particular case of the rule that if you do something to one side of an equation then you have to do the same thing to the other side and you have the same information that you started with.

This is useful to know when you are solving simultaneous equations.