This is a beginner video lesson (pre-algebra or 7th grade) explaining:
An equation is of the form (expression) = (expression). An equation can be a true or false equation. For example, 5 = 2 + 2 is a false equation.
If an equation contains an unknown, then solving the equation means finding the value of the unknown that makes the equation TRUE.
In the latter half of this lesson, we look at how a pan balance (scales) can model the process of solving equations. If we add the same amount to both sides of the balance, the sides will stay balanced (the weights stay equal). The same is true if we divide or multiply both sides by the same number.
Math Mammoth Grade 7 curriculum (pre-algebra)