Jon has 12 pennies. lucy has 17 pennies. how many more pennies do the need to have 75 pennies altogether ?

What are the solutions of the system? solve by graphing. y = -x^2 - 3x + 2 y = -2x + 2

Kelli swam upstream for some distance in a hour.she then swam downstream the same river for the same distance in only 6 minutes.if the river flows at 5km/hr, how fast can kelli swim in still water?

Find the area of the surface obtained by rotating the curve z=4e^2y from y = 0 to y =1 about the y-axis. the area is square units