Absolute value is a very important mathematical concept, which will be used in many mathematical problems. Here are some ways to solve problems by using absolute values:

1. Deciphering the sign of absolute value: Deciphering the sign of absolute value according to its basic properties is a common strategy to solve the absolute value problem.

2. Seek the maximum value: multi-letter evaluation can be realized by using the non-negativity of absolute value; Moreover, the multiplicity of absolute values can also be deeply understood here.

3. Prove inequalities: Many inequalities can be proved by absolute triangle inequalities.