You can
put this solution on YOUR website!The best place to start is the idea that the "=" sign is like
a balance point, and whatever you do to one side, you
must also do to the other side to keep the balance.
If I start with:

This is balanced
Now if I add

to just one side, I get

This is unbalanced
But if I now add

to the other side,

It's back in balance
This rule applies to addition, subtraction,
multiplication, and division