The average depth of water at a certain dock is 6 feet. This varies by 2 feet in both directions with the tide. Suppose high tide is at 4 AM and the tide goes from low to high every 7 hours. Write a function that can be use to express the height of the tide starting at 4 AM. Use "x" as your independent variable.​

Mrs. avila is buying a wallpaper border to go on all of her kitchen walls. she wants to buy 5 extra feet of wallpaper border than she needs to be sure she has enough. she buys 55.5 feet of the border. the store owner selling the border uses the width of mrs. avila's kitchen to determine that the length of her kitchen must be 14.5 feet.