Who's taking geometry and can help me?

Translate the word phrase into a math expression. 15 fewer than the product of 4 and a number. (pls immediately)

Simplify (a/b - b/a) times (a - a^2/a+b) a - a^2/a=b is a mixed number

The table below lists recommended amounts of food to order for 10 party guests. how much of each food item should nathan and amanda order for a graduation party with 55 guests? use the table to answer. item amount fried chicken 16 pieces lasagna 7 pounds deli meats 1.8 pounds sliced cheese 1 and two fifths pounds bakery buns 1 dozen potato salad 2 pounds