What are the slope and y-intercept of the linear function graphed to the left?

Which function is shown in the graph below?

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

1. a parachutist is 800 feet above the ground when she opens her parachute. she then falls at a constant rate of 5 feet per second. select the equation that represents this situation. h = -800t + 5 y = -5x + 800 h = 5t - 800 y = 800x + 5 i need