What is an equation?

I am not trying to make a definition of equation in this moment, but I will try to open your eyes in this sense when you solve word problems:

AN EQUATION IS A CONDITION

When we solve problems, we receive many data and CONDITIONS.

So, if we see an equation as a condition, we can easily find the way to the right answer:

Try to convert 

EACH CONDITION 

in 

ONE EQUATION

This is very important: if we receive one condition, there must be an equation to be used to solve the problem.

But if we receive two or more conditions, we must consider seriously the chance to look each condition as an equation, so we have to look for so many equations as conditions we find.

We are going to give you some examples of this soon.