What are the methods to solve the equation? What is the basis? How to test the solution of the equation?

1, the meaning of the equation: an equation with unknowns.

The equation must be an unknown value for the equation to be valid.

Methods of solving equations: denominator, parentheses, merging similar terms, shifting, coefficient to 1.

Test method: left and right substitution, left and right are equal.

2. Analyze the meaning of the question, set the unknown quantity appropriately, and find the equivalence relation.