Which relation is a function?

Ascale drawing of a lake has a scale of 1 cm to 80 m. if the actual width of the lake is 1000 m what is the width of the lake on the scale drawing

A20? -foot ladder is placed against a vertical wall of a? building, with the bottom of the ladder standing on level ground 19 feet from the base of the building. how high up the wall does the ladder? reach?

The manufacturer of a new product developed the following expression to predict the monthly profit, in thousands of dollars, from sales of the productwhen it is sold at a unit price of x dollars.-0.5x^2 + 22x - 224what is represented by the zero(s) of the expression? a.the profit when the unit price is equal to 0b.the unit price(s) when the profit is equal to 0c.the profit when the unit price is greatestd.the unit price(s) when profit is greatest