The formula that uses the symbol ">" "< to represent the relationship between size is called inequality. An inequality represented by "≦" is also an inequality.

Usually the number in inequality is a real number, and letters also represent real numbers. The general form of inequality is F(x, y, ..., z)≤G(x, y, ..., z) (where inequality can also be one of them), and the common domain of analytic expressions on both sides is called the domain of inequality. Inequality can express both a proposition and a problem.

1 inequality 1: the same number (or formula) is added (or subtracted) on both sides of the inequality at the same time, and the direction of the inequality remains unchanged;

2 Inequality 2: Both sides of the inequality are multiplied (or divided) by the same positive number at the same time, and the direction of the inequality remains unchanged;

3 Inequality 3: Both sides of the inequality are multiplied (or divided) by the same negative number at the same time, and the direction of the inequality changes. Summary: when the product of two positive numbers is constant, their sum has a minimum value; When the sum of two positive numbers is constant, their product has a maximum value.

I hope it can help you solve the problem.