46 Chapter 1 LINEAR FUNCTIONS AND CHANGE 13. The volume is going up by 10 gallons per hour, and In Exercises 3-5, give the units of the slope of the linear there are 4 gallons in the barrel now. function. 14. Without a calculator, match the systems of inequalities 3. The amount, A, of water flowing over a dam, in gallons, (a)-(d) to the graphs (1)-(IV). Give reasons. is a linear function of time, t, in minutes. 4. The distance, D, of an object from a point, in feet, is a (a) y 2 x and y 0, B > O, C> 0 (b) Write a linear equation whose graph cannot be seen (ii) A > 0, B > ,C 0, B 0 shown. 25. Fill in the missing coordinates for the points in the fol- 29. The graphical interpretation of the slope is that it shows lowing figures. steepness. Using a calculator or a computer, graph the function y = 2x - 3 in the following windows: (a) The triangle in Figure 1.56. (a) -10