It takes 3 hours to paddle a kayak 12 miles downstream and 4 hours for the return trip upstream. Find the rate of the kayak in still water. Let k= the rate of the kayak in still water and c= the rate of the current.

r t d rt=d
Downstream k+c 3 12 3(k+c)=12
Upstream k − c 4 12 4(k – c)=12

The rate of the kayak in still water is
4
miles per hour.

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