The equation for the height of a baseball being thrown directly up in the air at any time x is y = 16x^2+50x+4. What does the 4 represent

Use set builder notation to represent the following set: { -3, -2, -1, 0}

Evaluate the expression. (9 + 5)(3 + 2)0

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?