The subtraction operation of rational numbers (formulas) can be used to compare the sizes of two rational numbers (formulas), which is the "difference method". Comparing the sizes of two rational numbers (formulas) A and B, we can first find out the difference A-B between A and B, and then judge according to the results.

Prove a>b, then only A-B >; 0. This is the "difference comparison method".

The analysis is as follows:

example

The method of comparing the sizes of two real numbers is the difference method: Steps: ① Make the difference between the two numbers; ② Compare the differences with the size of 0; 3 draw a conclusion?

This method of using difference converts the ratio of two numbers or two formulas into difference sum? 0. It is to compare the size of Central Africa.

Always remember to master important methods.