Linear equations definition for 2nd grade

A linear equation is when you have 1 answer only in your equation. For a 2nd grader like you, then an example of a linear equation is the simple addition, subtraction, multiplication, and division. I guess you tackled these basic mathematics and it is just like a linear equation. If you will go to higher education or get into algebra, then your linear equation will be y=x+b where y and x are your variables and b is a constant or number that is given.