A catering company uses different functions to estimate the itemized costs for a party. The table below represents the included tip for wait staff as a function of the number of guests served.

Which equations represents circles that have a diameter of 12 units and a center that lies on the y-axis? check all that apply

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

How is working backward similar to solving an equation?