We can divide the equations in textbooks into three categories: general equations, special equations and slightly complicated equations.

For example: x+a=b, x-a=b, ax=b, x+a=b, we can call it a general equation. A-x=b and a+X=b can be called special equations. AX+B = C and A (X-B) = C can be called slightly complicated equations. We know that for a general equation, if a is added to the equation, a will be subtracted from both sides of the equation when solving by using the properties of the equation. Similarly, if a is used to subtract the equation, one will be added to both sides of the equation when solving it by using the properties of the equation. Multiplication and division are the same. In other words, addition, subtraction, multiplication and division are opposites, and addition, subtraction, multiplication and division are concrete numbers.

To sum up-in a word:-the general equation is very simple, and the specific numbers will be given to you, but addition, subtraction, multiplication and division should be the opposite. For a special equation, subtraction and division are both unknowns X. When solving, subtract the unknowns, then add them, add the unknowns, divide them by the unknowns, and then multiply them, with opposite signs. Thus, the equation is transformed into a general equation, which can be summarized as follows: don't be difficult for special equations, do subtraction and division with unknowns, and then multiply them to become a general equation.

For a slightly more complicated equation, the way I teach my children is to "keep the distance from the unknown X", that is, first remove those far from the unknown X and regard those far from the unknown X as a whole. Through transformation, the equation becomes simple and clear at a glance. To sum up: if it's a little complicated, it's easy to get out.