A quadratic equation is a polynomial equation in which a single variable appears in a 2nd-degree term, and all other terms are 1st degree or less. A quadratic inequality is a quadratic equation in which the equal sign has been replaced by an inequality symbol.
The relation of selection A would not be a quadratic equation if the relation symbol were an equal sign, hence it is not a quadratic inequality. The best choice is
15/100 * 20, because the meal is 20 dollars and to find the percent of something you divide it with 100 so you will divide 15 with 100 and you’ll get 0.15. Then you will times it with the amount the meal cost because thats the charge. So 0.15•20 and you’ll get $3. A 15% tip for a $20 meal is $3.